LUCA2 and Antibodies That Bind Thereto

ABSTRACT

The invention provides the identification and characterization of disease and cancer-associated antigen, LUCA2. The invention also provides a family of monoclonal antibodies that bind to antigen LUCA2, methods of diagnosing and treating various human cancers and diseases that express LUCA2.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 11/344,814 (filed on Jan. 31, 2006, pending), which applicationclaims priority to U.S. Patent Application Ser. No. 60/649,007 (filedJan. 31, 2005; expired), both of which applications are hereinincorporated by reference in their entireties.

TECHNICAL FIELD

This invention is in the fields of biology and immunotherapy. Morespecifically, it concerns a novel disease and cancer-associated antigen,LUCA2, and polyclonal and monoclonal antibodies and other polypeptidesthat bind to LUCA2. The invention further provides the diagnosis and/ortreatment of a variety of human diseases and cancers associated withLUCA2 using antagonists, modulators and peptides that bind to LUCA2,including anti-LUCA2 antibodies.

BACKGROUND OF THE INVENTION

In addition to their known uses in diagnostics, antibodies have beenshown to be useful as therapeutic agents. For example, immunotherapy, orthe use of antibodies for therapeutic purposes has been used in recentyears to, treat cancer. Passive immunotherapy involves the use ofmonoclonal antibodies in cancer treatments. See for example, Cancer:Principles and Practice of Oncology, 6^(th) Edition (2001) Chapt. 20 pp.495-508. These antibodies can have inherent therapeutic biologicalactivity both by direct inhibition of tumor cell growth or survival andby their ability to recruit the natural cell killing activity of thebody's immune system. These agents can be administered alone or inconjunction with radiation or chemotherapeutic agents. Rituximab andTrastuzumab, approved for treatment of non-Hodgkin's lymphoma and breastcancer, respectively, are two examples of such therapeutics.Alternatively, antibodies can be used to make antibody conjugates wherethe antibody is linked to a toxic agent and directs that agent to thetumor by specifically binding to the tumor. Gemtuzumab ozogamicin is anexample of an approved antibody conjugate used for the treatment ofleukemia. Monoclonal antibodies that bind to cancer cells and havepotential uses for diagnosis and therapy have been disclosed inpublications. See, for example, the following patent applications whichdisclose, inter alia, some molecular weights of target proteins: U.S.Pat. No. 6,054,561 (200 kD c-erbB-2 (Her2), and other unknown antigens40-200 KD in size) and U.S. Pat. No. 5,656,444 (50 kD and 55 kDoncofetal protein). Example of antibodies in clinical trials and/orapproved for treatment of solid tumors include: Trastuzumab (antigen:180 kD, HER2/neu), Edrecolomab (antigen: 40-50 kD, EpCAM), Anti-humanmilk fat globules (HMFG1) (antigen >200 kD, HMW Mucin), Cetuximab(antigens: 150 kD and 170 kD, EGF receptor), Alemtuzumab (antigen: 21-28kD, CD52), and Rituximab (antigen: 35 kD, CD20).

The antigen targets of trastuzumab (Her-2 receptor), which is used totreat breast cancer, and cetuximab (EGF receptor), which is in clinicaltrials for the treatment of several cancers, are present at somedetectable level on a large number of normal human adult tissuesincluding skin, colon, lung, ovary, liver, and pancreas. The margin ofsafety in using these therapeutics is possibly provided by thedifference in the level of expression or in access of or activity of theantibody at these sites. In addition to cancer targets, antibodytherapeutics have also been shown to be effective against chronicinflammation and other immune disorders. An example of an antibodytherapeutic approved for treatment of immune disorders is Infliximab(antigen: TNFa).

Another type of immunotherapy is active immunotherapy, or vaccination,with an antigen present on a specific cancer(s) or a DNA construct thatdirects the expression of the antigen, which then evokes the immuneresponse in the individual, i.e., to induce the individual to activelyproduce antibodies against their own cancer. Active immunization has notbeen used as often as passive immunotherapy or immunotoxins.

Several models of disease (including cancer) progression have beensuggested. Theories range from causation by. a singleinfective/transforming event to the evolution of an increasingly“disease-like” or “cancer-like” tissue type leading ultimately to onewith fully pathogenic or malignant capability. Some argue that withcancer, for example, a single mutational event is sufficient to causemalignancy, while others argue that subsequent alterations are alsonecessary. Some others have suggested that increasing mutational loadand tumor grade are necessary for both initiation as well as progressionof neoplasia via a continuum of mutation-selection events at thecellular level. Some cancer targets are found only in tumor tissues,while others are present in normal tissues and are up regulated and/orover-expressed in tumor tissues. In such situations, some researchershave suggested that the over-expression is linked to the acquisition ofmalignancy, while others suggest that the over-expression is merely amarker of a trend along a path to an increasing disease state.

An ideal diagnostic and/or therapeutic antibody would be specific for anantigen present on a large number of cancers, but absent or present onlyat low levels on any normal tissue. The discovery, characterization, andisolation of a novel antigen that is specifically associated withcancer(s) would be useful in many ways. First, the antigen could be usedto make monoclonal antibodies against the antigen. An antibody wouldideally have biological activity against cancer cells and be able torecruit the immune system's response to foreign antigens. An antibodycould be administered as a therapeutic alone or in combination withcurrent treatments or used to prepare immunoconjugates linked to toxicagents. An antibody with the same specificity but with low or nobiological activity when administered alone could also be useful in thatan antibody could be used to prepare an immunoconjugate with aradio-isotope, a toxin, or a chemotherapeutic agent or liposomecontaining a chemotherapeutic agent, with the conjugated form beingbiologically active by virtue of the antibody directing the toxin to theantigen-containing cells.

One aspect desirable for an ideal diagnostic and therapeutic antibody isthe discovery and characterization of an antigen that is associated witha variety of cancers. There are few antigens that are expressed on anumber of types of cancer (e.g., “pan-cancer” antigen) that have limitedexpression on non-cancerous cells. The isolation and purification ofsuch an antigen would be useful for making antibodies (e.g., diagnosticor therapeutic) targeting the antigen. An antibody binding to the“pan-cancer” antigen could be able to target a variety of cancers foundin different tissues in contrast to an antibody against an antigenassociated with only one specific type of cancer. The antigen would alsobe useful for drug discovery (e.g., small molecules) and for furthercharacterization of cellular regulation, growth, and differentiation.

What is needed are novel targets on the surface of diseased and/orcancer cells that may be used to diagnose and treat such diseases and/orcancers with antibodies and other agents which specifically recognizethe cell surface targets. There exists a further need, based on thediscoveries disclosed herein, for novel antibodies and other agentswhich specifically recognize targets on the surface of cells that canmodulate, either by reducing or enhancing, the disease-promotingactivities of LUCA2. It is an object of this invention to identifyantagonists of human LUCA2 that are capable of inhibiting itsdisease-associated activities. It is another object to provide novelcompounds for use in the assay of LUCA2, and for use as immunogens orfor selecting anti-human LUCA2 antibodies.

As will be described in more detail below, the present inventors havediscovered a novel antigen, which we refer to herein as LUCA2,identified as the antigen target of the novel antagonists, modulatorsand antibodies provided herein.

SUMMARY OF THE INVENTION

The invention provides for LUCA2 antagonists, modulators, and monoclonalantibodies that bind to LUCA2, which is expressed on a variety of humancancers. LUCA2 is a novel N-linked carbohydrate target expressed on avariety of cells, such as epithelial cells and neutrophils. In oneaspect, the invention is a family of monoclonal antibodies that bind toLUCA2.

In another aspect, the invention is a monoclonal antibody anti-LUCA2that is produced by the host cell line CA130.14H2.1A5 deposited on Mar.20, 2003 at the American Type Culture Collection with a Patent DepositDesignation of PTA# 5068.

In yet another aspect, the invention is a method of generatingmonoclonal antibody anti-LUCA2 reactive with diseased and/or cancerouscells comprising the steps of: (a) immunizing a host mammal with animmunogen; (b) obtaining lymphocytes from the mammal; (c) fusinglymphocytes (b) with a myeloma cell line to produce a hybridoma; (d)culturing the hybridoma of (c) to produce monoclonal antibodies; and (e)screening the antibodies to select only those antibodies which bind todiseased and/or cancerous cells or cell lines but do not bind tonon-cancerous or normal cells or cell lines, or bind to normal cells ata lower level or in a different fashion.

In another aspect, the invention is a method of generating an anti-LUCA2antibody comprising culturing a host cell encoding such antibody orprogeny thereof under conditions that allow production of the antibody,and purifying the anti-LUCA2 antibody.

In another aspect, the invention provides methods of generating any ofthe antibodies (or polypeptides) described herein by expressing one ormore polynucleotides encoding the antibody (which may be separatelyexpressed as a single light or heavy chain, or both a light and a heavychain are expressed from one vector) in a suitable cell, generallyfollowed by recovering and/or isolating the antibody or polypeptides ofinterest.

In another aspect, the invention is an anti-LUCA2 antibody or apolypeptide (which may or may not be an antibody) that competitivelyinhibits preferential binding of an anti-LUCA2 antibody to LUCA2. Insome embodiments, the invention is an antibody or a polypeptide (whichmay or may not be an antibody) that binds preferentially to the same ordifferent epitope(s) on LUCA2 as other anti-LUCA2 antibodies.

In another aspect, the invention is an LUCA2 modulator (which may or maynot be a polypeptide) that competitively inhibits preferential bindingof an anti-LUCA2 antibody to LUCA2. In some embodiments, the inventioncan be a small molecule or chemical compound that binds preferentiallyto the same or different epitope(s) on LUCA2 as other anti-LUCA2antibodies.

In yet another aspect, the invention is a composition comprising LUCA2bound by an antibody specific for an epitope of LUCA2. In oneembodiment, the antibody is anti-LUCA2. In other embodiments, two ormore anti-LUCA2 antibodies are administered, with such antibodiesmapping to two or more different epitopes on LUCA2. In some embodiments,the anti-LUCA2 antibody is linked to a therapeutic agent or a detectablelabel.

In another aspect, the invention is an antibody comprising a fragment ora region of an anti-LUCA2 antibody. In one embodiment, the fragment is alight chain of the antibody. In another embodiment, the fragment is aheavy chain of the antibody. In yet another embodiment, the fragmentcontains one or more variable regions from a light chain and/or a heavychain of the antibody. In yet another embodiment, the fragment containsone or more complementarity determining regions (CDRs) from a lightchain and/or a heavy chain of the antibody.

In another aspect, the invention provides polypeptides (which may or maynot be antibodies) comprising any of the following: (a) one or more CDRs(or fragments thereof) from the light or heavy chain; (b) three CDRsfrom the light chain; (c) three CDRs from the heavy chain; (d) threeCDRs from the light chain and three CDRs from the heavy chain; (e) thelight chain variable region; (f) the heavy chain variable region of theanti-LUCA2 antibody.

In another aspect, the invention is a humanized antibody. In someembodiments, the humanized antibody comprises one or more CDRs of anon-human anti-LUCA2 antibody. In some embodiments, the humanizedantibody binds to the same or different epitope(s) as other anti-LUCA2antibodies. Generally, a humanized antibody of the invention comprisesone or more (one, two, three, four, five, six or fragments thereof) CDRswhich are the same and/or derived from the CDR(s) of the originalnon-human anti-LUCA2 antibody. In some embodiments, the human antibodybinds to the same or different epitope(s) as other anti-LUCA2antibodies. In another aspect, the invention is a chimeric antibodycomprising variable regions derived from variable regions of a heavychain and a light chain of a non-human anti-LUCA2 antibody and constantregions derived from constant regions of a heavy chain and a light chainof a human antibody.

In another aspect, the invention is an isolated polynucleotide thatencodes an antibody mu-anti-LUCA2 that is produced by a host cell with adeposit number of ATCC PTA# 5068, or progeny thereof. This inventionencompasses antibody polypeptides having the inherent binding orbiological activities of any of the above-specified antibodies. Inanother aspect, the invention provides polynucleotides encoding any ofthe antibodies (including antibody fragments) as well as any otherpolypeptides described herein.

In another aspect, the invention is a pharmaceutical compositioncomprising any of the polypeptides (including any of the antibodiesdescribed herein) or polynucleotides described herein, such aspharmaceutical compositions comprising an anti-LUCA1 antibody linked toa chemotherapeutic agent, an antibody comprising a fragment of ananti-LUCA2 antibody, a humanized antibody of a non-human LUCA2 antibody,a chimeric antibody comprising variable regions derived from variableregions of a non-human anti-LUCA2 antibody and constant regions derivedfrom a human antibody, or a human antibody with one or more propertiesof a non-human anti-LUCA2 antibody, or of the anti-LUCA2 antibodydescribed herein linked to a chemotherapeutic agent (such as aradioactive moiety), and a pharmaceutically acceptable excipient.

In one aspect, the invention is a composition comprising an anti-LUCA2antibody bound to LUCA2 present on a diseased or cancerous cell. Inpreferred embodiments, the cancer cell is selected from the groupconsisting of kidney, ovarian, lung, prostate, pancreatic, colon, andbreast cancer cells. In some embodiments, the cancer cell is isolated.In some embodiments, the cancer cell is in a biological sample.Generally, the biological sample is from an individual, such as a human.

In another aspect, the invention is a method of diagnosing disease in anindividual by detecting LUCA2 on cells from the individual, particularlydiseases or disorders associated with inflammatory or autoimmuneresponses in individuals. In other aspects of the invention, methods areprovided for modulating inflammatory or autoimmune responses inindividuals by modulating LUCA2 function. Diseases and conditionsresulting from inflammation and autoimmune disorders that may be subjectto treatment using the compositions and methods of the inventioninclude, by way of illustration and not of limitation, multiplesclerosis, meningitis, encephalitis, stroke, other cerebral traumas,inflammatory bowel disease including ulcerative colitis and Crohn'sdisease, myasthenia gravis, lupus, rheumatoid arthritis, asthma, acutejuvenile onset diabetes, AIDS dementia, atherosclerosis, nephritis,retinitis, atopic dermatitis, psoriasis, myocardial ischemia and acuteleukocyte-mediated lung injury.

Still other indications for therapeutic use of antibodies and othertherapeutic agents of the invention include administration toindividuals at risk of organ or graft rejection. Over recent years therehas been a considerable improvement in the efficiency of surgicaltechniques for transplanting tissues and organs such as skin, kidney,liver, heart, lung, pancreas and bone marrow. Perhaps the principaloutstanding problem is the lack of satisfactory agents for inducingimmunotolerance in the recipient to the transplanted allograft or organ.When allogeneic cells or organs are transplanted into a host (i.e., thedonor and donee are different individuals from the same species), thehost immune system is likely to mount an immune response to foreignantigens in the transplant (host-versus-graft disease) leading todestruction of the transplanted tissue.

In another aspect, the invention is a method for diagnosing whether anindividual has cancer, comprising determining whether there isexpression of LUCA2 on selected cells from the individual, wherein theexpression of LUCA2 on said cells is indicative of said cancer. In someembodiments, the expression of LUCA2 is determined using an anti-LUCA2antibody. In some embodiments, the method involves detecting the levelof LUCA2 expression from cells. The term “detection” as used hereinincludes qualitative and/or quantitative detection (measuring levels)with or without reference to a control.

In yet another aspect, the invention is a method of diagnosing cancer inan individual by detecting LUCA2 on or released from cells from theindividual, wherein the cancer is selected from the group including butnot limited to adrenal gland tumors, AIDS-associated cancers, alveolarsoft part sarcoma, astrocytic tumors, bladder cancer (squamous cellcarcinoma and transitional cell carcinoma), bone cancer (adamantinoma,aneurismal bone cysts, osteochondroma, osteosarcoma), brain and spinalcord cancers, metastatic brain tumors, breast cancer, carotid bodytumors, cervical cancer, chondrosarcoma, dhordoma, chromophobe renalcell carcinoma, clear cell carcinoma, colon cancer, colorectal cancer,cutaneous benign fibrous histiocytomas, desmoplastic small round celltumors, ependymomas, Ewing's tumors, extraskeletal myxoidchondrosarcoma, fibrogenesis imperfecta ossium, fibrous dysplasia of thebone, gallbladder and bile duct cancers, gestational trophoblasticdisease, germ cell tumors, head and neck cancers, islet cell tumors,Kaposi's Sarcoma, kidney cancer (nephroblastoma, papillary renal cellcarcinoma), leukemias, lipoma/benign lipomatous tumors,liposarcoma/malignant lipomatous tumors, liver cancer (hepatoblastoma,hepatocellular carcinoma), lymphomas, lung cancer, medulloblastoma,melanoma, meningiomas, multiple endocrine neoplasia, multiple myeloma,myelodysplastic syndrome, neuroblastoma, neuroendocrine tumors, ovariancancer, pancreatic cancers, papillary thyroid carcinomas, parathyroidtumors, pediatric cancers, peripheral nerve sheath tumors,phaeochromocytoma, pituitary tumors, prostate cancer, posterious unvealmelanoma, rare hematologic disorders, renal metastatic cancer, rhabdoidtumor, rhabdomysarcoma, sarcomas, skin cancer, soft-tissue sarcomas,squamous cell cancer, stomach cancer, synovial sarcoma, testicularcancer, thymic carcinoma, thymoma, thyroid metastatic cancer, anduterine cancers (carcinoma of the cervix, endometrial carcinoma, andleiomyoma).

In another aspect, the invention is a method for aiding diagnosis ofcancer (such as but not limited to kidney, ovarian, lung, prostate,pancreatic, colon, or breast cancer) in an individual comprisingdetermining the expression of LUCA2 in a biological sample from theindividual. In some embodiments, the expression of LUCA2 is determinedusing an anti-LUCA2 antibody. In some embodiments, the method isdetecting the level of LUCA2 expression from cells. The LUCA2 releasedfrom the cancer may contribute to elevated levels of LUCA2 or a portionthereof, being detectable in body fluids (e.g., blood, salivary or gutmucinous secretions).

In yet another aspect, the invention is a method of treating cancer byadministering an effective amount of an antibody that binds to LUCA2sufficient to reduce growth of cancerous cells. In some embodiments, theantibody is an anti-LUCA2 antibody. In certain embodiments, thecancerous cells are selected from the group including but not limited toadrenal gland tumors, AIDS-associated cancers, alveolar soft partsarcoma, astrocytic tumors, bladder cancer (squamous cell carcinoma andtransitional cell carcinoma), bone cancer (adamantinoma, aneurismal bonecysts, osteochondroma, osteosarcoma), brain and spinal cord cancers,metastatic brain tumors, breast cancer, carotid body tumors, cervicalcancer, chondrosarcoma, dhordoma, chromophobe renal cell carcinoma,clear cell carcinoma, colon cancer, colorectal cancer, cutaneous benignfibrous histiocytomas, desmoplastic small round cell tumors,ependymomas, Ewing's tumors, extraskeletal myxoid chondrosarcoma,fibrogenesis imperfecta ossium, fibrous dysplasia of the bone,gallbladder and bile duct cancers, gestational trophoblastic disease,germ cell tumors, head and neck cancers, islet cell tumors, Kaposi'sSarcoma, kidney cancer (nephroblastoma, papillary renal cell carcinoma),leukemias, lipoma/benign lipomatous tumors, liposarcoma/malignantlipomatous tumors, liver cancer (hepatoblastoma, hepatocellularcarcinoma), lymphomas, lung cancer, medulloblastoma, melanoma,meningiomas, multiple endocrine neoplasia, multiple myeloma,myelodysplastic syndrome, neuroblastoma, neuroendocrine tumors, ovariancancer, pancreatic cancers, papillary thyroid carcinomas, parathyroidtumors, pediatric cancers, peripheral nerve sheath tumors,phaeochromocytoma, pituitary tumors, prostate cancer, posterious unvealmelanoma, rare hematologic disorders, renal metastatic cancer, rhabdoidtumor, rhabdomysarcoma, sarcomas, skin cancer, soft-tissue sarcomas,squamous cell cancer, stomach cancer, synovial sarcoma, testicularcancer, thymic carcinoma, thymoma, thyroid metastatic cancer, anduterine cancers (carcinoma of the cervix, endometrial carcinoma, andleiomyoma). In certain preferred embodiments, the cancerous cells areselected from the group of solid tumors including but not limited tobreast cancer, colon cancer, prostate cancer, lung cancer, sarcoma,renal metastatic cancer, thyroid metastatic cancer, and clear cellcarcinoma.

In yet another aspect, the invention is a method of delaying developmentof metastasis in an individual having cancer comprising administering aneffective amount of at least one of a family of antibodies that bindspecifically to LUCA2. In one embodiment, the antibody is an anti-LUCA2antibody. In another aspect, the invention is a method of inhibitinggrowth and/or proliferation of cancer cells in vitro or in an individualcomprising administering an effective amount of a composition comprisingan anti-LUCA2 antibody associated with (including linked to) achemotherapeutic agent to the cell culture or sample, or to theindividual.

In yet another aspect, the invention is a method of delivering atherapeutic agent to a cancerous cell in an individual by administeringto the individual an effective amount of at least one member of a familyof antibodies, which bind specifically to LUCA2. In other embodiments,an anti-LUCA2 antibody is delivered to an individual in combination with(including linked to) another therapeutic agent.

In some embodiments, the anti-LUCA2 antibody is a humanized antibodyderived from a named antibody herein (generally, but not necessarily,comprising one or more partial or intact CDRs of the antibody). In someembodiments, the anti-LUCA2 antibody is a human antibody with one ormore properties of the named antibody. In some embodiments, thechemotherapeutic agent (such as a toxin or a radioactive molecule) isdelivered into the cancer cells (is internalized). In some embodiments,the agent is saporin.

In another aspect, the invention is a method of treating cancer in anindividual comprising administering an effective amount of a compositioncomprising an anti-LUCA2 antibody associated with (including linked to)a chemotherapeutic agent to the individual.

The present invention further provides methods for modulating, either byenhancing or reducing, the association of LUCA2 with a cytoplasmicsignaling partner. The association of LUCA2 with a cytoplasmic signalingpartner can be impacted by contacting a LUCA2 molecule presenting on acell surface, with an agent that modulates the binding of the signalingpartner to LUCA2. Agents which block or reduce LUCA2 association withits binding and/or signaling partners can be used to modulate biologicaland pathological processes which are involved in LUCA2-mediatedinflammation or immune responses. Pathological processes involving thisaction include tumor-associated cell growth.

Agents can be tested for their ability to block, reduce, enhance orotherwise modulate the association of LUCA2 with a binding partner, suchas an anti-LUCA2 antibody. Specifically, an agent can be tested for theability to modulate such an interaction by incubating a peptidecomprising the LUCA2 interaction site (typically in its nativeconformation as it exists on intact living cells) with a binding partnerand a test agent, and determining whether the test agent reduces orenhances the binding of the binding partner to the LUCA2 peptide.

Agonists, antagonists, and other modulators of LUCA2 function areexpressly included within the scope of this invention. These agonists,antagonists and modulators are polypeptides that comprise one or more ofthe antigenic determinant sites in LUCA2, or comprise one or morefragments of such sites, variants of such sites, or peptidomimetics ofsuch sites. These agonistic, antagonistic, and LUCA2 modulatorycompounds are provided in linear or cyclized form, and optionallycomprise at least one amino acid residue that is not commonly found innature or at least one amide isostere. These compounds may beglycosylated. The agonists, antagonists, and other modulators of LUCA2function of this invention are desirably used in all of the embodimentsand methods described above with reference to antibodies.

Other aspects of this invention relate to the novel antigen identifiedand referred to herein as LUCA2. This antigen is suitable for use as animmunogen and for a variety of research, diagnostic and therapeuticpurposes.

In certain aspects, the invention is a method for aiding in thediagnosis of disease in an individual comprising the steps of (i)assaying for the presence of LUCA2 in a blood or tissue sample obtainedfrom an individual; (ii) detecting whether said sample has an increasedamount of a LUCA2 marker relative to a normal (non-diseased) blood ortissue sample; and (iii) correlating an increased amount of said markerto a positive diagnosis or correlating the absence of an increasedamount of said marker to a negative diagnosis for disease. In certainembodiments, the marker is detected using an anti-LUCA2 antibody. Incertain embodiments, the method is effected by a technique selected fromthe group consisting of radionuclide imaging, flow cytometry, andimmunohistochemistry.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an immunoprecipitation using mu-anti-LUCA2 antibodies orcontrol IgG on cellular lysates of colorectal adenocarcinoma cell linesHT-29 and Colo205 and then western blotted with mu-anti-LUCA2antibodies. The arrows point to specific doublet bands that is presentin HT-29 and Colo205 cell lysates and not present in control celllysates.

FIG. 2 is an immunoprecipitation and Western blot of LUCA2 from normalhuman neutrophils and treated with different glycanases. Lane 1 showsLUCA2 purified from normal human neutrophils without glycanasetreatment. The double arrows show the mu-anti-LUCA2 specific bands. Lane2 shows LUCA2 treated with N-glycanase. Lane 3 shows LUCA2 treated withN-glycanase and S-glycanase. Lane 4 shows LUCA2 treated withO-glycanase. Lane 5 show LUCA2 treated with N, S, and O-glycanase.

FIG. 3 shows the graphed results of mu-anti-LUCA2 in an ELISA assayusing Lewis B antigen, Lewis A antigen, Lewis O antigen and lactoN-difucohexose I.

FIG. 3 is a graph showing an ELISA using mu-anti-LUCA2 and fourdifferent glyco-analogs: LNFP-I (Lewis B antigen), LNFP-II (Lewis Aantigen), LNFP-III (Lewis X antigen) and LNDFP-1 (Lacto-N-difucohexaoseI).

FIG. 4 is a graph showing the effects of mu-anti-LUCA2 on Mac-1(CD11b/CD18) mediated T84 cell adhesion.

FIG. 5 is a graph showing the in vitro activity of mu-anti-LUCA2 on thegrowth of the pancreatic adenocarcinoma cell line, Hs700T.

FIG. 6 shows the graphed results of the effect of mu-anti-LUCA2 andMab-ZAP (an anti-IgG conjugate to saporin) on the growth of humanpancreatic adenocarcinoma cell line Hs700T. Open circles representcontrol samples with Mab-ZAP alone and closed circles represent sampleswith mu-anti-LUCA2 and Mab-ZAP.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a novel antigen, LUCA2, which is expressed oncancerous cells of various tissue types, including but not limited tobreast, colon, lung, and prostate cancers. LUCA2 is an N-linkedcarbohydrate epitope found on a variety of cells and proteins, forexample it is found on epithelial cells and neutrophils. On neutrophilsit can be found on MAC-1 (CD11b/CD18). Further, the invention providesmonoclonal antibodies and polypeptides that bind to LUCA2 and methodsmaking and using these antibodies and polypeptides to diagnose and treatvarious diseases, such as human cancers associated with expressionand/or over-expression of LUCA2, and various human diseases involvingautoimmune response and/or chronic inflammation.

I. General Techniques

The practice of the present invention will employ, unless otherwiseindicated, conventional techniques of molecular biology (includingrecombinant techniques), microbiology, cell biology, biochemistry andimmunology, which are within the skill of the art. Such techniques areexplained fully in the literature, such as, Molecular Cloning: ALaboratory Manual, second edition (Sambrook et al., 1989) Cold SpringHarbor Press; Oligonucleotide Synthesis (M. J. Gait, ed., 1984); Methodsin Molecular Biology, Humana Press; Cell Biology: A Laboratory Notebook(J. E. Cellis, ed., 1998) Academic Press; Animal Cell Culture (R. I.Freshney, ed., 1987); Introduction to Cell and Tissue Culture (J. P.Mather and P. E. Roberts, 1998) Plenum Press; Cell and Tissue Culture:Laboratory Procedures (A. Doyle, J. B. Griffiths, and D. G. Newell,eds., 1993-8) J. Wiley and Sons; Methods in Enzymology (Academic Press,Inc.); Handbook of Experimental Immunology (D. M. Weir and C. C.Blackwell, eds.); Gene Transfer Vectors for Mammalian Cells (J. M.Miller and M. P. Calos, eds., 1987); Current Protocols in MolecularBiology (F. M. Ausubel et al., eds., 1987); PCR: The Polymerase ChainReaction, (Mullis et al., eds., 1994); Current Protocols in Immunology(J. E. Coligan et al., eds., 1991); Short Protocols in Molecular Biology(Wiley and Sons, 1999); Immunobiology (C. A. Janeway and P. Travers,1997); Antibodies (P. Finch, 1997); Antibodies: a practical approach (D.Catty., ed., IRL Press, 1988-1989); Monoclonal antibodies: a practicalapproach (P. Shepherd and C. Dean, eds., Oxford University Press, 2000);Using antibodies: a laboratory manual (E. Harlow and D. Lane (ColdSpring Harbor Laboratory Press, 1999); The Antibodies (M. Zanetti and J.D. Capra, eds., Harwood Academic Publishers, 1995); and Cancer:Principles and Practice of Oncology (V. T. DeVita et al., eds., J. B.Lippincott Company, 1993).

II. Definitions

“LUCA2” refers to that novel antigen epitope that is present onpolypeptides with a molecular weight of approximately 150 kDa and 210kDa doublet against which the antibodies of the present invention aredirected. LUCA2 is present on cell surface protein bound by anti-LUCA2antibodies and present on colon and duodenum and several types ofcarcinomas. This antigen maybe present on more than one polypeptide. Itis currently believed that LUCA2 may be over-expressed in certain cancercells in comparison to their normal tissue counterparts.

Agonists, antagonists, and other modulators of LUCA2 function areexpressly included within the scope of this invention. These agonists,antagonists and modulators are polypeptides that comprise one or more ofthe antigenic determinant sites in LUCA2, or comprise one or morefragments of such sites, variants of such sites, or peptidomimetics ofsuch sites. These agonistic, antagonistic, and LUCA2 modulatorycompounds are provided in linear or cyclized form, and optionallycomprise at least one amino acid residue that is not commonly found innature or at least one amide isostere. These compounds may beglycosylated.

More specifically, the terms “LUCA2 modulator” as used herein aredefined as any compound that (1) is capable of disrupting or blockingthe interaction between human LUCA2 and its native ligands or ananti-LUCA2 antibody; (2) is capable of binding to human LUCA2 and itsnative ligands or an anti-LUCA2 antibody; (3) contains an antigenic sitethat can be used in the raising of antibodies capable of binding tohuman LUCA2 and its native ligands or an anti-LUCA2 antibody; (4)contains an antigenic site that can be used in the screening ofantibodies capable of binding to human LUCA2 and its native ligands oran anti-LUCA2 antibody; (5) contains an antigenic site that an be usedin the raising of antibodies capable of disrupting or blocking theinteraction between human LUCA2 and its native ligands or an anti-LUCA2antibody; (6) contains an antigenic site that can be used in thescreening of antibodies capable of disrupting or blocking theinteraction between human LUCA2 and its native ligands or an anti-LUCA2antibody. LUCA2 modulators may be “LUCA2 agonists” or “LUCA2antagonists” depending on whether their activity enhances or inhibitsnormal LUCA2 biological activity, respectively.

LUCA2 agonists, antagonists and modulators include LUCA2 variants, LUCA2peptide antagonists, peptidomimetics, and small molecules, anti-LUCA2antibodies and immunoglobulin variants, amino acid variants of humanLUCA2 including amino acid substitution, deletion, and additionvariants, or any combination thereof, and chimeric immunoglobulins. TheLUCA2 agonists, antagonists and modulators of this invention are basedon the inventors' identification of the LUCA2 domains involved in thebinding of human LUCA2 to its native ligands or anti-LUCA2 antibodies.Thus, the invention provides LUCA2 agonists, antagonists and modulatorswith molecular structures that duplicate or mimic one or more of theanti-LUCA2 binding domains of human LUCA2.

As used herein, the term “LUCA2 variant” denotes any amino acid variantof human LUCA2, including amino acid substitution, deletion, andaddition variants, or any combination thereof. The definitionencompasses chimeric molecules such as human LUCA2/non-human chimerasand other hybrid molecules. Also included in the definition is anyfragment of a LUCA2 variant molecule that comprises the variant orhybrid region(s) of the molecule.

An “antibody” is an immunoglobulin molecule capable of specific bindingto a target, such as a carbohydrate, polynucleotide, lipid, polypeptide,etc., through at least one antigen recognition site, located in thevariable region of the immunoglobulin molecule. As used herein, the termencompasses not only intact polyclonal or monoclonal antibodies, butalso fragments thereof (such as Fab, Fab′, F(ab′)₂, Fv), single chain(ScFv), mutants thereof, naturally occurring variants, fusion proteinscomprising an antibody portion with an antigen recognition site of therequired specificity, humanized antibodies, chimeric antibodies, and anyother modified configuration of the immunoglobulin molecule thatcomprises an antigen recognition site of the required specificity.

A “monoclonal antibody” refers to a homogeneous antibody populationwherein the monoclonal antibody is comprised of amino acids (naturallyoccurring and non-naturally occurring) that are involved in theselective binding of an antigen. Monoclonal antibodies are highlyspecific, being directed against a single antigenic site. The term“monoclonal antibody” encompasses not only intact monoclonal antibodiesand full-length monoclonal antibodies, but also fragments thereof (suchas Fab, Fab′, F(ab′)₂, Fv), single chain (ScFv), mutants thereof, fusionproteins comprising an antibody portion, humanized monoclonalantibodies, chimeric monoclonal antibodies, and any other modifiedconfiguration of the immunoglobulin molecule that comprises an antigenrecognition site of the required specificity and the ability to bind toan antigen. It is not intended to be limited as regards to the source ofthe antibody or the manner in which it is made (e.g., by hybridoma,phage selection, recombinant expression, transgenic animals, etc.). Theterm includes whole immunoglobulins as well as the fragments etc.described above under the definition of “antibody”.

“Humanized” antibodies refer to a chimeric molecule, generally preparedusing recombinant techniques, having an antigen binding site derivedfrom an immunoglobulin from a non-human species and the remainingimmunoglobulin structure of the molecule based upon the structure and/orsequence of a human immunoglobulin. The antigen-binding site maycomprise either complete variable domains fused onto constant domains oronly the complementarity determining regions (CDRs) grafted ontoappropriate framework regions in the variable domains. Antigen bindingsites may be wild type or modified by one or more amino acidsubstitutions. This eliminates the constant region as an immunogen inhuman individuals, but the possibility of an immune response to theforeign variable region remains (LoBuglio, A. F. et al., (1989) ProcNatl Acad Sci USA 86:4220-4224). Another approach focuses not only onproviding human-derived constant regions, but modifying the variableregions as well so as to reshape them as closely as possible to humanform. It is known that the variable regions of both heavy and lightchains contain three complementarity-determining regions (CDRs) whichvary in response to the antigens in question and determine bindingcapability, flanked by four framework regions (FRs) which are relativelyconserved in a given species and which putatively provide a scaffoldingfor the CDRs. When nonhuman antibodies are prepared with respect to aparticular antigen, the variable regions can be “reshaped” or“humanized” by grafting CDRs derived from nonhuman antibody on the FRspresent in the human antibody to be modified. Application of thisapproach to various antibodies has been reported by Sato, K., et al.,(1993) Cancer Res 53:851-856. Riechmann, L., et al., (1988) Nature332:323-327; Verhoeyen, M., et al., (1988) Science 239:1534-1536;Kettleborough, C. A., et al., (1991) Protein Engineering 4:773-3783;Maeda, H., et al., (1991) Human Antibodies Hybridoma 2:124-134; Gorman,S. D., et al., (1991) Proc Natl Acad Sci USA 88:4181-4185; Tempest, P.R., et al., (1991) Bio/Technology 9:266-271; Co, M. S., et al., (1991)Proc Natl Acad Sci USA 88:2869-2873; Carter, P., et al., (1992) ProcNatl Acad Sci USA 89:4285-4289; and Co, M. S. et al., (1992) J Immunol148:1149-1154. In some embodiments, humanized antibodies preserve allCDR sequences (for example, a humanized mouse antibody which containsall six CDRs from the mouse antibodies). In other embodiments, humanizedantibodies have one or more CDRs (one, two, three, four, five, six)which are altered with respect to the original antibody, which are alsotermed one or more CDRs “derived from” one or more CDRs from theoriginal antibody.

An epitope that “specifically binds” or “preferentially binds” (usedinterchangeably herein) to an antibody or a polypeptide is a term wellunderstood in the art, and methods to determine such specific orpreferential binding are also well known in the art. A molecule is saidto exhibit “specific binding” or “preferential binding” if it reacts orassociates more frequently, more rapidly, with greater duration and/orwith greater affinity with a particular cell or substance than it doeswith alternative cells or substances. An antibody “specifically binds”or “preferentially binds” to a target if it binds with greater affinity,avidity, more readily, and/or with greater duration than it binds toother substances. For example, an antibody that specifically orpreferentially binds to a LUCA2 epitope is an antibody that binds thisLUCA2 epitope with greater affinity, avidity, more readily, and withgreater duration than it binds to other LUCA2 epitopes or non-LUCA2epitopes. It is also understood by reading this definition that, forexample, an antibody (or moiety or epitope) that specifically orpreferentially binds to a first target may or may not specifically orpreferentially bind to a second target. As such, “specific binding” or“preferential binding” does not necessarily require (although it caninclude) exclusive binding. Generally, but not necessarily, reference tobinding means preferential binding.

The term “immunologically active” in reference to an epitope being or“remaining immunologically active” refers to the ability of an antibody(e.g., anti-LUCA2 antibody) to bind to the epitope under differentconditions, for example, after the epitope has been subjected toreducing and denaturing conditions.

Different biological functions are associated with anti-LUCA2antibodies, including, but not limited to, ability to bind to LUCA2(including LUCA2 on cancer cells, including but not limited topancreatic, lung, kidney, breast, colon and prostate cancer cells);ability to bind to a portion of LUCA2 that is exposed on the surface ofa living cell in vitro or in vivo; ability to deliver a chemotherapeuticagent to cancerous cells (pancreatic, lung, kidney, breast, colon andprostate cancer cells) expressing LUCA2; ability to deliver atherapeutic agent or detectable marker into cancer cells expressingLUCA2. As discussed herein, polypeptides (including antibodies) of theinvention may have any one or more of these characteristics.

An “anti-LUCA2 equivalent antibody” or “anti-LUCA2 equivalentpolypeptide” refers to an antibody or a polypeptide having one or morebiological functions associated with an anti-LUCA2 antibody, such as,for example binding specificity.

As used herein, “agent” refers to a biological, pharmaceutical, orchemical compound. Non-limiting examples include simple or complexorganic or inorganic molecule, a peptide, a protein, an oligonucleotide,an antibody, an antibody derivative, antibody fragment, a vitaminderivative, a carbohydrate, a toxin, or a chemotherapeutic compound.Various compounds can be synthesized, for example, small molecules andoligomers (e.g., oligopeptides and oligonucleotides), and syntheticorganic compounds based on various core structures. In addition, variousnatural sources can provide compounds for screening, such as plant oranimal extracts, and the like. A skilled artisan can readily recognizethat there is no limit as to the structural nature of the agents of thepresent invention.

Agents that are employed in the methods of this invention can berandomly selected or rationally selected or designed. As used herein, anagent is said to be randomly selected when the agent is chosen randomlywithout considering the specific sequences involved in the associationof LUCA2 with its native binding partners or known antibodies. Anexample of randomly selected agents is the use of a chemical library ora peptide combinatorial library.

As used herein, an agent is said to be rationally selected or designedwhen the agent is chosen on a nonrandom basis that takes into accountthe sequence of the target site and/or its conformation in connectionwith the agent's action. With respect to anti-LUCA2 agents, it iscurrently believed that there are at least three epitopes on LUCA2against which antibodies can be raised and therefore at least threesites of action for agents that block LUCA2/anti-LUCA2 interaction. Thisinvention also encompasses agents that act at the sites of interactionbetween LUCA2 and its native binding partner, although other ligands andtheir active LUCA2-interactive sites are also encompassed within thescope of this invention, whether currently known or later identified.Agents can be rationally selected or rationally designed by utilizingthe peptide sequences that make up the contact sites of thereceptor/ligand and LUCA2/anti-LUCA2 antibody complex. For example, arationally selected peptide agent can be a peptide whose amino acidsequence is identical to an epitope appearing on LUCA2 as it is exposedon the surface of a living cell in its native environment. Such an agentwill reduce or block the association of the anti-LUCA2 antibody withLUCA2, or the association of LUCA2 with its native ligand, as desired,by binding to the anti-LUCA2 antibody or to the native ligand.

As used herein, the term “labeled”, with regard to the antibody, isintended to encompass direct labeling of the antibody by coupling (i.e.,physically linking) a detectable substance, such as a radioactive agentor a fluorophore (e.g. fluorescein isothiocyanate (FITC) orphycoerythrin (PE)) to the antibody, as well as indirect labeling of theprobe or antibody by reactivity with a detectable substance.

As used herein, the term “association”, with regard to the antibody,includes covalent and non-covalent attachment or binding to an agent(e.g., chemotherapeutic agent). The antibody can be associated with anagent (e.g., chemotherapeutic agent) by direct binding or indirectbinding via attachment to a common platform, such that the antibodydirects the localization of the agent to the cancerous cell to which theantibody binds and wherein the antibody and agent do not substantiallydissociate under physiological conditions such that the agent is nottargeted to the same cancerous cell to which the antibody binds or suchthat the agent's potency is not decreased.

A “biological sample” encompasses a variety of sample types obtainedfrom an individual and can be used in a diagnostic or monitoring assay.The definition encompasses saliva, blood and other liquid samples ofbiological origin, solid tissue samples such as a biopsy specimen ortissue cultures or cells derived therefrom, and the progeny thereof, forexample, cells obtained from a tissue sample collected from anindividual suspected of having cancer, in preferred embodiments frompancreas, lung, kidney, breast, colon and prostate tissue. Thedefinition also includes samples that have been manipulated in any wayafter their procurement, such as by treatment with reagents,solubilization, or enrichment for certain components, such as proteinsor polynucleotides, or embedding in a semi-solid or solid matrix forsectioning purposes. The term “biological sample” encompasses a clinicalsample, and also includes cells in culture, cell supernatants, celllysates, serum, plasma, biological fluid, and tissue samples.

A “host cell” includes an individual cell or cell culture that can be orhas been a recipient for vector(s) for incorporation of polynucleotideinserts. Host cells include progeny of a single host cell, and theprogeny may not necessarily be completely identical (in morphology or ingenomic DNA complement) to the original parent cell due to natural,accidental, or deliberate mutation. A host cell includes cellstransfected in vivo with a polynucleotide(s) of this invention.

As used herein, “delaying development of metastasis” means to defer,hinder, slow, retard, stabilize, and/or postpone development ofmetastasis. This delay can be of varying lengths of time, depending onthe history of the cancer and/or individual being treated. As is evidentto one skilled in the art, a sufficient or significant delay can, ineffect, encompass prevention, in that the individual does not developthe metastasis.

An “effective amount” of a pharmaceutical composition, in oneembodiment, is an amount sufficient to effect beneficial or desiredresults including, without limitation, clinical results such asshrinking the size of the tumor (in the cancer context, for example,breast or prostate cancer), retardation of cancerous cell growth,delaying the development of metastasis, decreasing symptoms resultingfrom the disease, increasing the quality of life of those suffering fromthe disease, decreasing the dose of other medications required to treatthe disease, enhancing the effect of another medication such as viatargeting and/or internalization, delaying the progression of thedisease, and/or prolonging survival of individuals. An effective amountcan be administered in one or more administrations. For purposes of thisinvention, an effective amount of drug, compound, or pharmaceuticalcomposition is an amount sufficient to reduce the proliferation of (ordestroy) cancerous cells and to reduce and/or delay the development, orgrowth, of metastases of cancerous cells, either directly or indirectly.In some embodiments, an effective amount of a drug, compound, orpharmaceutical composition may or may not be achieved in conjunctionwith another drug, compound, or pharmaceutical composition. Thus, an“effective amount” may be considered in the context of administering oneor more chemotherapeutic agents, and a single agent may be considered tobe given in an effective amount if, in conjunction with one or moreother agents, a desirable result may be or is achieved. While individualneeds vary, determination of optimal ranges of effective amounts of eachcomponent is within the skill of the art. Typical dosages comprise 0.1-to 100 mg/kg/body weight. The preferred dosages comprise 1- to100-mg/kg/body weight. The most preferred dosages comprise 10- to100-mg/kg/body weight.

As used herein, a nucleic acid molecule or agent, antibody, compositionor cell, etc., is said to be “isolated” when that nucleic acid molecule,agent, antibody, composition, or cell, etc. is substantially separatedfrom contaminant nucleic acid molecules, antibodies, agents,compositions, or cells, etc. from its original source.

An “individual” is a vertebrate, preferably a mammal, more preferably ahuman. Mammals include, but are not limited to, farm animals, sportanimals, pets, primates, mice and rats.

The terms “polypeptide”, “oligopeptide”, “peptide” and “protein” areused interchangeably herein to refer to polymers of amino acids of anylength. The polymer may be linear or branched, it may comprise modifiedamino acids, and it may be interrupted by non-amino acids. The termsalso encompass an amino acid polymer that has been modified naturally orby intervention; for example, disulfide bond formation, glycosylation,lipidation, acetylation, phosphorylation, or any other manipulation ormodification, such as conjugation with a labeling component. Alsoincluded within the definition are, for example, polypeptides containingone or more analogs of an amino acid (including, for example, unnaturalamino acids, etc.), as well as other modifications known in the art. Itis understood that, because the polypeptides of this invention are basedupon an antibody, the polypeptides can occur as single chains orassociated chains.

Also encompassed within the scope of the invention are peptidomimeticsof the LUCA2 peptide agonists, antagonists and modulators (includinganti-LUCA2 antibodies) described herein. Such peptidomimetics includepeptides wherein at least one amino acid residue is substituted with anamino acid residue that is not commonly found in nature, such as the Disomer of the amino acid or an N-alkylated species of the amino acid. Inother embodiments, peptidomimetics are constructed by replacing at leastone amide bond (—C(.dbd.O)—NH—) in a LUCA2 peptide agonist, antagonistor modulators with an amide isostere. Suitable amide isosteres include—CH.sub.2-NH—, —CH.sub.2-CH.sub.2-S(O).sub.n- (where n is 1 or 2),—CH.sub.2-CH.sub.2-CH.dbd.CH— (E or Z), —C(.dbd.O)—CH.sub.2-CH(CN)—NH—,—C(OH)—CH.sub.2-, and —O—C(.dbd.O)—NH—. The amide bonds in a LUCA2peptide agonist, antagonist or modulator that are suitable candidatesfor replacement with amide isosteres include bonds that are hydrolyzableby the endogenous esterases or proteases of the intended subject ofLUCA2 peptide agonist, antagonist or modulator treatment.

As used herein, “substantially pure” refers to material that is at least50% pure (i.e., free from contaminants), more preferably at least 90%pure, more preferably at least 95% pure, more preferably at least 98%pure, more preferably at least 99% pure, or greater, pure.

“Toxin” refers to any substance, which effects an adverse responsewithin a cell. For example, a toxin directed to a cancerous cell wouldhave an adverse, sometimes deleterious effect, on the cancerous cell.Examples of toxins include, but are not limited to, radioisotopes,calicheamicin, and maytansinoids.

As used herein, “treatment” or “treating” is an approach for obtainingbeneficial or desired results including and preferably clinical results.For purposes of this invention, beneficial or desired clinical resultsinclude, but are not limited to, one or more of the following: reducingthe proliferation of (or destroying) cancerous cells or other diseased,reducing metastasis of cancerous cells found in cancers, shrinking thesize of the tumor, decreasing symptoms resulting from the disease,increasing the quality of life of those suffering from the disease,decreasing the dose of other medications required to treat the disease,delaying the progression of the disease, and prolonging survival ofindividuals.

III. Methods of Making Antibodies and Polypeptides

Methods of making monoclonal antibodies are known in the art. One methodwhich may be employed is the method of Kohler and Milstein, Nature256:495-497 (1975) or a modification thereof. Typically, monoclonalantibodies are developed in non-human species, such as mice. In general,a mouse or rat is used for immunization but other animals may also beused. The antibodies are produced by immunizing mice with an immunogenicamount of cells, cell extracts, or protein preparations that containhuman LUCA2. The immunogen can be, but is not limited to, primary cells,cultured cell lines, cancerous cells, nucleic acids, or tissue. In oneembodiment, human lung carcinoma cells are used. In another embodiment,human bladder or pancreatic progenitor cells are used. Methods forisolating and culturing human lung carcinoma cells are detailed inExample 1. Cells used for immunization, for example, human lungcarcinoma cells, bladder cells or human pancreatic progenitor cells, maybe cultured for a period of time (at least 24 hours) prior to their useas an immunogen. Cells (e.g., human lung carcinoma cells, other cells orcell lines expressing LUCA2) may be used as immunogens by themselves orin combination with a non-denaturing adjuvant, such as Ribi. In general,cells should be kept intact and preferably viable when used asimmunogens. Intact cells may allow antigens to be better detected thanruptured cells by the immunized animal. Use of denaturing or harshadjuvants, e.g., Freud's adjuvant, may rupture the human fetal kidney orother cells and therefore is discouraged. The immunogen may beadministered multiple times at periodic intervals such as, bi-weekly, orweekly, or may be administered in such a way as to maintain viability inthe animal (e.g., in a tissue recombinant). Example 2 describes methodsused to generate anti-LUCA2 antibodies and may be used to generate othermonoclonal antibodies, which bind to LUCA2.

In one embodiment, monoclonal antibodies, which bind to LUCA2 areobtained by using host cells that over-express LUCA2 as an immunogen.Such cells include, by way of example and not by limitation, human lungcarcinoma cells.

To monitor the antibody response, a small biological sample (e.g.,blood) may be obtained from the animal and tested for antibody titeragainst the immunogen. The spleen and/or several large lymph nodes canbe removed and dissociated into single cells. If desired, the spleencells may be screened (after removal of non-specifically adherent cells)by applying a cell suspension to a plate or to a well coated with theantigen. B-cells, expressing membrane-bound immunoglobulin specific forthe antigen, will bind to the plate, and are not rinsed away with therest of the suspension. Resulting B-cells, or all dissociated spleencells, can then be fused with myeloma cells (e.g., X63-Ag8.653 and thosefrom the Salk Institute, Cell Distribution Center, San Diego, Calif.).Polyethylene glycol (PEG) may be used to fuse spleen or lymphocytes withmyeloma cells to form a hybridoma. The hybridoma is then cultured in aselective medium (e.g., hypoxanthine, aminopterin, thymidine medium,otherwise known as “HAT medium”). The resulting hybridomas are thenplated by limiting dilution, and are assayed for the production ofantibodies that bind specifically to the immunogen (e.g., surface of thehuman fetal kidney cells, surface of cancer cell lines, Ag-LUCA2, fetalbladder sections, etc.) using FACS or immunohistochemistry (IHCscreening). The selected monoclonal antibody-secreting hybridomas arethen cultured either in vitro (e.g., in tissue culture bottles or hollowfiber reactors), or in vivo (e.g., as ascites in mice). Example 3provides further details about the methods utilized to obtain and screenan anti-LUCA2 antibody.

As another alternative to the cell fusion technique, EBV immortalized Bcells may be used to produce monoclonal antibodies of the subjectinvention. The hybridomas are expanded and subcloned, if desired, andsupernatants are assayed for anti-immunogen activity by conventionalassay procedures (e.g., FACS, IHC, radioimmunoassay, enzyme immunoassay,fluorescence immunoassay, etc.).

In another alternative, monoclonal antibody anti-LUCA2 and any otherequivalent antibodies can be sequenced and produced recombinantly by anymeans known in the art (e.g., humanization, use of transgenic mice toproduce fully human antibodies, phage display technology, etc.). In oneembodiment, anti-LUCA2 monoclonal antibody is sequenced and thepolynucleotide sequence is then cloned into a vector for expression orpropagation. The sequence encoding the antibody of interest may bemaintained in a vector in a host cell and the host cell can then beexpanded and frozen for future use.

The polynucleotide sequence of monoclonal antibody anti-LUCA2 and anyother equivalent antibodies may be used for genetic manipulation togenerate a “humanized” antibody, to improve the affinity, or othercharacteristics of the antibody. The general principle in humanizing anantibody involves retaining the basic sequence of the antigen-bindingportion of the antibody, while swapping the non-human remainder of theantibody with human antibody sequences. There are four general steps tohumanize a monoclonal antibody. These are: (1) determining thenucleotide and predicted amino acid sequence of the starting antibodylight and heavy variable domains (2) designing the humanized antibody,i.e., deciding which antibody framework region to use during thehumanizing process (3) the actual humanizing methodologies/techniquesand (4) the transfection and expression of the humanized antibody. See,for example, U.S. Pat. Nos. 4,816,567; 5,807,715; 5,866,692; and6,331,415.

A number of “humanized” antibody molecules comprising an antigen-bindingsite derived from a non-human immunoglobulin have been described,including chimeric antibodies having rodent or modified rodent V regionsand their associated complementarity determining regions (CDRs) fused tohuman constant domains. See, for example, Winter et al. Nature349:293-299 (1991), Lobuglio et al. Proc. Nat. Acad. Sci. USA86:4220-4224 (1989), Shaw et al. J. Immunol. 138:4534-4538 (1987), andBrown et al. Cancer Res. 47:3577-3583 (1987). Other references describerodent CDRs grafted into a human supporting framework region (FR) priorto fusion with an appropriate human antibody constant domain. See, forexample, Riechmann et al. Nature 332:323-327 (1988), Verhoeyen et al.Science 239:1534-1536 (1988), and Jones et al. Nature 321:522-525(1986). Another reference describes rodent CDRs supported byrecombinantly veneered rodent framework regions. See, for example,European Patent Publication No. 519,596. These “humanized” molecules aredesigned to minimize unwanted immunological response toward rodentanti-human antibody molecules, which limits the duration andeffectiveness of therapeutic applications of those moieties in humanrecipients. Other methods of humanizing antibodies that may also beutilized are disclosed by Daugherty et al., Nucl. Acids Res.,19:2471-2476 (1991) and in U.S. Pat. Nos. 6,180,377; 6,054,297;5,997,867; and 5,866,692.

The invention also encompasses single chain variable region fragments(“scFv”) of antibodies of this invention, such as mu-anti-LUCA2. Singlechain variable region fragments are made by linking light and/or heavychain variable regions by using a short linking peptide. Bird et al.(1988) Science 242: 423-426 describes example of linking peptides whichbridge approximately 3.5 nm between the carboxy terminus of one variableregion and the amino terminus of the other variable region. Linkers ofother sequences have been designed and used, Bird et al. (1988). Linkerscan in turn be modified for additional functions, such as attachment ofdrugs or attachment to solid supports. The single chain variants can beproduced either recombinantly or synthetically. For synthetic productionof scFv, an automated synthesizer can be used. For recombinantproduction of scFv, a suitable plasmid containing polynucleotide thatencodes the scFv can be introduced into a suitable host cell, eithereukaryotic, such as yeast, plant, insect or mammalian cells, orprokaryotic, such as E. coli. Polynucleotides encoding the scFv ofinterest can be made by routine manipulations such as ligation ofpolynucleotides. The resultant scFv can be isolated using standardprotein purification techniques known in the art.

The invention includes modifications to LUCA2 agonists, antagonists,modulators and antibodies, including functionally equivalent antibodiesand polypeptides that do not significantly affect their properties andvariants that have enhanced or decreased activity. Modification ofpolypeptides is routine practice in the art and need not be described indetail herein. Examples of modified polypeptides include polypeptideswith conservative substitutions of amino acid residues, one or moredeletions or additions of amino acids which do not significantlydeleteriously change the functional activity, or use of chemicalanalogs. Amino acid residues which can be conservatively substituted forone another include but are not limited to: glycine/alanine;valine/isoleucine/leucine; asparagine/glutamine; aspartic acid/glutamicacid; serine/threonine; lysine/arginine; and phenylalanine/tryosine.These polypeptides also include glycosylated and nonglycosylatedpolypeptides, as well as polypeptides with other post-translationalmodifications, such as, for example, glycosylation with differentsugars, acetylation, and phosphorylation. Preferably, the amino acidsubstitutions would be conservative, i.e., the substituted amino acidwould possess similar chemical properties as that of the original aminoacid. Such conservative substitutions are known in the art, and exampleshave been provided above. Amino acid modifications can range fromchanging or modifying one or more amino acids to complete redesign of aregion, such as the variable region. Changes in the variable region canalter binding affinity and specificity. Other methods of modificationinclude using coupling techniques known in the art, including, but notlimited to, enzymatic means, oxidative substitution and chelation.Modifications can be used, for example, for attachment of labels forimmunoassay, such as the attachment of radioactive moieties forradioimmunoassay. Modified polypeptides are made using establishedprocedures in the art and can be screened using standard assays known inthe art.

The invention also encompasses fusion proteins comprising one or morefragments or regions from the polypeptides and antibodies of thisinvention. In one embodiment, a fusion polypeptide is provided thatcomprises at least 10 contiguous amino acids of variable light chainregion and at least 10 amino acids of variable heavy chain region. Inanother embodiment, the fusion polypeptide contains a heterologousimmunoglobulin constant region. In another embodiment, the fusionpolypeptide contains a light chain variable region and a heavy chainvariable region of an antibody produced from a hybridoma deposited withthe ATCC as described herein. For purposes of this invention, anantibody fusion protein contains one or more anti-LUCA2 polypeptides andanother amino acid sequence to which it is not attached in the nativemolecule, for example, a heterologous sequence or a homologous sequencefrom another region.

An anti-LUCA2 polypeptide, and other LUCA2 agonists, antagonists andmodulators can be created by methods known in the art, for example,synthetically or recombinantly. One method of producing LUCA2 peptideagonists, antagonists and modulators involves chemical synthesis of thepolypeptide, followed by treatment under oxidizing conditionsappropriate to obtain the native conformation, that is, the correctdisulfide bond linkages. This can be accomplished using methodologieswell known to those skilled in the art (see Kelley, R. F. & Winkler, M.E. in Genetic Engineering Principles and Methods, Setlow, J. K., ed.,Plenum Press, N.Y., vol. 12, pp 1-19 (1990); Stewart, J. M. & Young, J.D. Solid Phase Peptide Synthesis Pierce Chemical Co. Rockford, Ill.(1984); see also U.S. Pat. Nos. 4,105,603; 3,972,859; 3,842,067; and3,862,925).

Polypeptides of the invention may be conveniently prepared using solidphase peptide synthesis (Merrifield, J. Am. Chem. Soc., 85:2149 (1964);Houghten, Proc. Natl. Acad. Sci. USA 82:5132 (1985)).

In yet another alternative, fully human antibodies may be obtained byusing commercially available mice that have been engineered to expressspecific human immunoglobulin proteins. Transgenic animals that aredesigned to produce a more desirable (e.g., fully human antibodies) ormore robust immune response may also be used for generation of humanizedor human antibodies. Examples of such technology are Xenomouse™ fromAbgenix, Inc. (Fremont, Calif.) and HuMAb-Mouse® and TC Mouse™ fromMedarex, Inc. (Princeton, N.J.).

In an alternative, antibodies may be made recombinantly and expressedusing any method known in the art. Antibodies may be made recombinantlyby first isolating the antibodies made from host animals, obtaining thegene sequence, and using the gene sequence to express the antibodyrecombinantly in host cells (e.g., CHO cells). Another method that maybe employed is to express the antibody sequence in plants (e.g.,tobacco) or transgenic milk. Methods for expressing antibodiesrecombinantly in plants or milk have been disclosed. See, for example,Peeters, et al. (2001) Vaccine 19:2756; Lonberg, N. and D. Huszar (1995)Int. Rev. Immunol 13:65; and Pollock, et al. (1999) J Immunol Methods231:147. Methods for making derivatives of antibodies, e.g., humanized,single chain, etc. are known in the art. In another alternative,antibodies may be made recombinantly by phage display technology. See,for example, U.S. Pat. Nos. 5,565,332; 5,580,717; 5,733,743; 6,265,150;and Winter et al., Annu. Rev. Immunol. 12:433-455 (1994).

The antibodies or protein of interest may be subjected to sequencing byEdman degradation, which is well known to those of skill in the art. Thepeptide information generated from mass spectrometry or Edmandegradation can be used to design probes or primers that are used toclone the protein of interest.

An alternative method of cloning the protein of interest is by “panning”using purified LUCA2 or portions thereof for cells expressing theantibody or protein of interest. The “panning” procedure is conducted byobtaining a cDNA library from tissues or cells that express the antibodyor protein of interest; over-expressing the cDNAs in a second cell type,and screening the transfected cells of the second cell type for aspecific binding to LUCA2. Detailed descriptions of the methods used incloning mammalian genes coding for cell surface proteins by “panning”can be found in the art. See, for example, Aruffo, A. and Seed, B. Proc.Natl. Acad. Sci. USA, 84, 8573-8577 (1987) and Stephan, J. et al.,Endocrinology 140: 5841-5854 (1999).

cDNAs encoding anti-LUCA2 antibodies, and other LUCA2 peptide agonists,antagonists and modulators can be obtained by reverse transcribing themRNAs from a particular cell type according to standard methods in theart. Specifically, mRNA can be isolated using various lytic enzymes orchemical solutions according to the procedures set forth in Sambrook, etal. supra or extracted by commercially available nucleic-acid-bindingresins following the accompanying instructions provided by manufacturers(e.g., Qiagen, Invitrogen, Promega). The synthesized cDNAs are thenintroduced into an expression vector to produce the antibody or proteinof interest in cells of a second type. It is implied that an expressionvector must be replicable in the host cells either as episomes or as anintegral part of the chromosomal DNA. Suitable expression vectorsinclude but are not limited to plasmids, viral vectors, includingadenoviruses, adeno-associated viruses, retroviruses, and cosmids.

The vectors containing the polynucleotides of interest can be introducedinto the host cell by any of a number of appropriate means, includingelectroporation, transfection employing calcium chloride, rubidiumchloride, calcium phosphate, DEAE-dextran, or other substances;microprojectile bombardment; lipofection; and infection (e.g., where thevector is an infectious agent such as vaccinia virus). The choice ofintroducing vectors or polynucleotides will often depend on features ofthe host cell.

Any host cells capable of over-expressing heterologous DNAs can be usedfor the purpose of isolating the genes encoding the antibody,polypeptide or protein of interest. Non-limiting examples of mammalianhost cells include but not limited to COS, HeLa, and CHO cells.Preferably, the host cells express the cDNAs at a level of about 5 foldhigher, more preferably 10 fold higher, even more preferably 20 foldhigher than that of the corresponding endogenous antibody or protein ofinterest, if present, in the host cells. Screening the host cells for aspecific binding to LUCA2 is effected by an immunoassay or FACS. A cellover-expressing the antibody or protein of interest can be identified.

Various techniques are also available which may now be employed toproduce mutant LUCA2 peptide agonists, antagonists, and modulators whichencodes for additions, deletions, or changes in amino acid sequence ofthe resultant protein relative to the parent LUCA2 peptide agonist,antagonist or modulator molecule.

The invention includes polypeptides comprising an amino acid sequence ofthe antibodies of this invention. The polypeptides of this invention canbe made by procedures known in the art. The polypeptides can be producedby proteolytic or other degradation of the antibodies, by recombinantmethods (i.e., single or fusion polypeptides) as described above or bychemical synthesis. Polypeptides of the antibodies, especially shorterpolypeptides up to about 50 amino acids, are conveniently made bychemical synthesis. Methods of chemical synthesis are known in the artand are commercially available. For example, an anti-LUCA2 polypeptidecould be produced by an automated polypeptide synthesizer employing thesolid phase method.

IV. Methods for Screening Polypeptides and Monoclonal Antibodies

Several methods may be used to screen polypeptides and monoclonalantibodies that bind to LUCA2. It is understood that “binding” refers tobiologically or immunologically relevant binding, i.e., binding which isspecific for the unique antigen for which the immunoglobulin molecule isencoded, or to which the polypeptide is directed. It does not refer tonon-specific binding that may occur when an immunoglobulin is used at avery high concentration against a non-specific target. In oneembodiment, monoclonal antibodies are screened for binding to LUCA2using standard screening techniques. In this manner, anti-LUCA2monoclonal antibody was obtained. In accordance with the BudapestTreaty, a hybridoma which produces anti-LUCA2 monoclonal antibodies hasbeen deposited in the American Type Culture Collection (ATCC) 10801University Blvd., Manassas Va. 20110-2209 on Mar. 20, 2003 with a PatentDeposit Designation of PTA# 5068.

Monoclonal antibodies that bind to LUCA2 are screened for binding tocancerous tissues and non-cancerous cells. In one embodiment, monoclonalantibodies which bind to LUCA2 and that are also cross reactive to humancancerous cells or tissues, but not to normal cells or tissues to thesame degree, are selected. One method that may be employed for screeningis immunohistochemistry (IHC). Standard immunohistochemical techniquesare known to those of average skill in the art. See, for example, AnimalCell Culture Methods (J. P. Mather and D. Barnes, eds., Academic Press,Vol. 57, Ch. 18 and 19, pp. 314-350, 1998). Biological samples (e.g.,tissues) may be obtained from biopsies, autopsies, or necropsies. Toascertain if LUCA2 is present only on cancerous cells, anti-LUCA2antibodies may be used to detect the presence of LUCA2 on tissues fromindividuals with cancer while other non-cancerous tissues from theindividual suffering from cancer or tissues from individuals withoutcancer are used as a control. The tissue can be embedded in a solid orsemi-solid substance that prevents damage during freezing (e.g., agarosegel or OCT) and then sectioned for staining. Cancers from differentorgans and at different grades can be used to screen monoclonalantibodies. Examples of tissues that may be used for screening purposesinclude but are not limited to ovary, breast, lung, prostate, colon,kidney, skin, thyroid, brain, heart, liver, stomach, nerve, bloodvessels, bone, upper digestive tract, and pancreas. Examples ofdifferent cancer types that may be used for screening purposes includebut are not limited to carcinomas, adenocarcinomas, sarcomas,adenosarcomas, lymphomas, and leukemias.

In yet another alternative, cancerous cells lines such as HMEC(BioWhittaker CC-2251), HUVEC (Primary endothelial cells), BT-474 (ATCC#HTB-20), MFC7 (ATCC# HTB22), MDA-MB-175-VII (ATCC# HB-25), MDA-MB-361(ATCC# HB-27), SKBR3 (ATCC# HTB-30), 9979 (Raven proprietary lung cancercell line), A549 (ATCC# CCL-185), CA130 (Raven proprietary lung smallcell carcinoma cell line), Calu-3 (ATCC# HTB-55), SKMES-1 (ATCC#HTB-58), ES-2 (ATCC# CRL-1978), SKOV3 (ATCC# HTB-77), 9926 (Ravenproprietary pancreatic adenocarcinoma cell line), AsPC-1 (ATCC#CRL-1682), HPAF-II (ATCC# CRL-1997), Hs700T (ATCC# HTB-174), Colo205(ATCC# CCL-222), HT-29 (ATCC# HTB-38), SW480 (ATCC# CCL-228), SW948(ATCC# CCL-237), 293 (ATCC # CRL-1573), 786-0 (ATCC# CRL-1932), A498(ATCC# HTB-44), Caki-2 (ATCC# HTB-47), COS-7 (ATCC# CRL-1651), RL-65(ATCC # CRL-10345), SV-T2 (ATCC# CCL-163.1), 22RV1 (ATCC# CRL-2505),DU145 (ATCC# HTB-81), LNCaP (ATCC# CRL-1740), PC-3 (ATCC# CRL-1435), TDH(Raven proprietary prostate cancer cell line), Hs746T (ATCC# HTB-135),NCI-N87 (ATCC# CRL-5822) and normal cells from their respective tissuesmay be used to screen for monoclonal antibodies which are specific forcancerous tissue. Primary, or low passage, cell cultures derived fromnormal tissues from different organs, including but not limited to,kidney, ovary, breast, lung, prostate, colon, kidney, skin, thyroid,aortic smooth muscle, and endothelial cells can be used as negativecontrols. The cancerous or non-cancerous cells can be grown on glassslides or coverslips, or on plastic surfaces, or prepared in aCellArray™, as described in WO 01/43869, and screened for the binding ofantibody using IHC as described above for tissues. Alternatively, cellsmay be removed from the growth surface using non-proteolytic means andspun into a pellet, which is then embedded and treated as tissues forIHC analysis as described above. Cells may be inoculated intoimmunodeficient animals, a tumor allowed to grow, and then this tumormay be harvested, embedded, and used as a tissue source for IHCanalysis. In another alternative, single cells may be screened byincubating with the primary antibody, a secondary “reporter” antibodylinked to a fluorescent molecule and then analyzed using a fluorescentactivated cell-sorting (FACS) machine.

Several different detection systems may be utilized to detect binding ofantibodies to tissue section. Typically, immunohistochemistry involvesthe binding of a primary antibody to the tissue and then a secondaryantibody reactive against the species from the primary antibody wasgenerated and conjugated to a detectable marker (e.g., horseradishperoxidase, HRP, or diaminobenzedine, DAB). One alternative method thatmay be used is polyclonal mirror image complementary antibodies orpolyMICA. PolyMICA (polyclonal Mirror Image Complementary Antibodies)technique, described by D. C. Mangham and P. G. Isaacson (Histopathology(1999) 35(2):129-33), can be used to test binding of primary antibodies(e.g., anti-LUCA2 antibodies) to normal and cancerous tissue. Severalkinds of polyMICA™ Detection kits are commercially available from TheBinding Site Limited (P.O. Box 4073 Birmingham B29 6AT England). ProductNo. HK004.D is a polyMICAT™ Detection kit which uses DAB chromagen.Product No. HK004.A is a polyMICAT™ Detection kit which uses AECchromagen. Alternatively, the primary antibody may be directly labeledwith the detectable marker.

The first step in IHC screening to select for an appropriate antibody isthe binding of primary antibodies raised in mice (e.g., anti-LUCA2antibodies) to one or more immunogens (e.g., cells or tissue samples).In one embodiment, the tissue sample is sections of frozen tissue fromdifferent organs. The cells or tissue samples can be either cancerous ornon-cancerous.

Frozen tissues can be prepared, sectioned, with or without fixation, andIHC performed by any of a number of methods known to one familiar withthe art. See, for example, Stephan et al. Dev. Biol. 212: 264-277(1999), and Stephan et al. Endocrinology 140: 5841-54 (1999).

V. Methods of Characterizing Anti-LUCA2 Antibodies

Several methods can be used to characterize anti-LUCA2 antibodies. Onemethod is to identify the epitope to which it binds. Epitope mapping iscommercially available from various sources, for example, PepscanSystems (Edelhertweg 15, 8219 PH Lelystad, The Netherlands). Epitopemapping can be used to determine the sequence to which an anti-LUCA2antibody binds. The epitope can be a linear epitope, i.e., contained ina single stretch of amino acids, or a conformational epitope formed by athree-dimensional interaction of amino acids that may not necessarily becontained in a single stretch. Peptides of varying lengths (e.g., atleast 4-6 amino acids long) can be isolated or synthesized (e.g.,recombinantly) and used for binding assays with anti-LUCA2 antibody. Theepitope to which anti-LUCA2 antibody binds can be determined in asystematic screening by using overlapping peptides derived from theextracellular sequence and determining binding by anti-LUCA2 antibody.

Yet another method that can be used to characterize an anti-LUCA2antibody is to use competition assays with other antibodies known tobind to the same antigen, i.e., LUCA2 to determine if anti-LUCA2antibodies binds to the same epitope as other antibodies. Examples ofcommercially available antibodies to LUCA2 may be available and may beidentified using the binding assays taught herein. Competition assaysare well known to those of skill in the art, and such procedures andillustrative data are detailed further in the Examples. Anti-LUCA2antibodies can be further characterized by the tissues, type of canceror type of tumor to which they bind.

Another method of characterizing anti-LUCA2 antibodies is by the antigento which it binds. Anti-LUCA2 antibodies were used in Western blots withcell lysates from various human cancers. As is known to one of skill inthe art, Western blotting can involve running cell lysates and/or cellfractions on a denaturing or non-denaturing gel, transferring theproteins to nitrocellulose paper, and then probing the blot with anantibody (e.g., anti-LUCA2 antibody) to see which proteins are bound bythe antibody. This procedure is detailed further in Example 4. LUCA2 isassociated with various human cancers of different tissues including butnot limited to colon, breast, ovary, pancreas and lung. Furtherdescription of LUCA2 is given in Example 5 and 6.

VI. Methods of Diagnosing Cancer Using Anti-LUCA2 Antibodies and LUCA2Modulators

Monoclonal antibodies to LUCA2 made by the methods disclosed herein maybe used to identify the presence or absence of cancerous cells in avariety of tissues, including but not limited to, ovary, breast, lung,prostate, colon, kidney, pancreas, skin, thyroid, brain, heart, liver,stomach, nerve, blood vessels, bone, and upper digestive tract, forpurposes of diagnosis. Monoclonal antibodies to LUCA2 made by themethods disclosed herein may also be used to identify the presence orabsence of cancerous cells, or the level thereof, which are circulatingin blood after their release from a solid tumor. Such circulatingantigen may be an intact LUCA2 antigen, or a fragment thereof thatretains the ability to be detected according to the methods taughtherein. Such detection may be effected by FACS analysis using standardmethods commonly used in the art.

These uses can involve the formation of a complex between LUCA2 and anantibody that binds specifically to LUCA2. Examples of such antibodiesinclude but are not limited to those anti-LUCA2 monoclonal antibodiesproduced by the hybridoma deposited in the ATCC with the designationPTA# 5068. The formation of such a complex can be in vitro or in vivo.Without being bound by theory, monoclonal antibody anti-LUCA2 can bindto LUCA2 through the extracellular domain of LUCA2 and may then beinternalized.

In a preferred embodiment of the diagnostic methods of this invention,the antibody bears a detectable label. Examples of labels that may beused include a radioactive agent or a fluorophore, such asfluoroisothiocyanate or phycoerythrin.

As with other known antibodies used commercially for diagnostic andtherapeutic purposes, the target antigen of this invention is broadlyexpressed in normal tissue. It is also up regulated in some tumors.Therefore, the particular dosages and routes of delivery of theantibodies of this invention as used for diagnostic or therapeuticagents will be tailored to the particular tumor or disease state athand, as well as to the particular individual being treated.

One method of using the antibodies for diagnosis is in vivo tumorimaging by linking the antibody to a radioactive or radioopaque agent,administering the antibody to the individual and using an x-ray or otherimaging machine to visualize the localization of the labeled antibody atthe surface of cancer cells expressing the antigen. The antibody isadministered at a concentration that promotes binding at physiologicalconditions.

In vitro techniques for detection of LUCA2 are routine in the art andinclude enzyme linked immunosorbent assays (ELISAs),immunoprecipitations, immunofluorescence, enzyme immunoassay (EIA),radioimmunoassay (RIA), and Western blot analysis.

In aspects of this invention, methods of radioimaging of tumours orneoplasms, or of measuring the effectiveness of a method of treatmentwith a radiolabelled antibody, comprising the step of administering aradiolabelled, tumour-specific antibody to an individual following thepractice of this invention. The radiolabelled antibody may be amonoclonal or polyclonal antibody comprising a radiolabel, preferablyselected from the group consisting of Technetium-99m, Indium-111,Iodine-131, Rhenium-186, Rhenium-188, Samarium-153, Lutetium-177,Copper-64, Scandium-47, Yttrium-90. Monoclonal antibodies labelled withtherapeutic radionuclides such as Iodine-131, Rhenium-188, Holmium-166,Samarium-153 and Scandium-47, which do not compromise theimmunoreactivity of antibodies and are not broken down in vivo, areespecially preferred. The person skilled in the art will appreciate thatother radioactive isotopes are known, and may be suitable for specificapplications. The radioimaging may be conducted using Single. PhotonEmission Computer Tomography (SPECT), Position Emmission Tomography(PET), Computer Tomography (CT) or Magnetic Resonance Imaging (MRI).Correlative imaging, which permits greater anatomical definition oflocation of metastases located by radioimmunoimaging, is alsocontemplated.

In other methods, the cancerous cells are removed and the tissueprepared for immunohistochemistry by methods well known in the art(e.g., embedding in a freezing compound, freezing and sectioning, withor without fixation; fixation and paraffin embedding with or withoutvarious methods of antigen retrieval and counterstaining). Themonoclonal antibodies may also be used to identify cancerous cells atdifferent stages of development. The antibodies may also be used todetermine which individuals' tumors express the antigen on their surfaceat a pre-determined level and are thus candidates for immunotherapyusing antibodies directed against said antigen. The antibodies mayrecognize both primary and metastasizing cancers of the kidney, ovary,prostate and pancreas and primary cancers of the lung that expressLUCA2. As used herein, detection may include qualitative andquantitative detection and may include comparing the level measured to anormal cell for an increased level of expression of LUCA2 in cancerouscells.

The invention also provides methods of aiding diagnosis of cancer (suchas pancreas, lung, kidney, breast, colon and prostate cancer) in anindividual using any antibody that binds to LUCA2 and any other methodsthat can be used determine the level of LUCA2 expression. As usedherein, methods for “aiding diagnosis” means that these methods assistin making a clinical determination regarding the classification, ornature, of cancer, and may or may not be conclusive with respect to thedefinitive diagnosis. Accordingly, a method of aiding diagnosis ofcancer can comprise the step of detecting the level of LUCA2 in abiological sample from the individual and/or determining the level ofLUCA2 expression in the sample. Antibodies recognizing the antigen or aportion thereof may also be used to create diagnostic immunoassays fordetecting antigen released or secreted from living or dying cancer cellsin bodily fluids, including but not limited to, blood, saliva, urine,pulmonary fluid, or ascites fluid.

Not all cells in a particular tumor of interest will express LUCA2, andcancerous cells in other tissues may express LUCA2, thus an individualshould be screened for the presence or absence of LUCA2 on cancerouscells to determine the usefulness of immunotherapy in the individual.The anti-LUCA2 antibodies made by the methods disclosed herein may beused to determine whether an individual diagnosed with cancer may bedeemed a candidate for immunotherapy using antibodies directed againstLUCA2. In one embodiment, a cancerous tumor or a biopsy sample may betested for expression of LUCA2, using antibodies directed against LUCA2.Individuals with cancer cells that express LUCA2 are suitable candidatesfor immunotherapy using antibodies directed against LUCA2. Staining withanti-LUCA2 antibody may also be used to distinguish cancerous tissuesfrom normal tissues.

Methods of using anti-LUCA2 antibodies for diagnostic purposes areuseful both before and after any form of anti-cancer treatment, e.g.,chemotherapy or radiation therapy, to determine which tumors are mostlikely to respond to a given treatment, prognosis for individual withcancer, tumor subtype or origin of metastatic disease, and progressionof the disease or response to treatment.

The compositions of this invention are also suitable for diagnosis ofdisease states other than cancer, using the methods generally describedabove in application with other diseased (non-cancerous) cells. Diseasestates suitable for use in the methods of this invention include, butare not limited to, diseases or disorders associated with inflammatoryor autoimmune responses in individuals. The methods described above maybe used for modulating inflammatory or autoimmune responses inindividuals. Diseases and conditions resulting from inflammation andautoimmune disorders that may be subject to diagnosis and treatmentusing the compositions and methods of the invention include, by way ofillustration and not of limitation, multiple sclerosis, meningitis,encephalitis, stroke, other cerebral traumas, inflammatory bowel diseaseincluding ulcerative colitis and Crohn's disease, myasthenia gravis,lupus, rheumatoid arthritis, asthma, acute juvenile onset diabetes, AIDSdementia, atherosclerosis, nephritis, retinitis, atopic dermatitis,psoriasis, myocardial ischemia and acute leukocyte-mediated lung injury.

Still other indications for diagnostic and/or therapeutic use ofantibodies and other therapeutic agents of the invention includeadministration to individuals at risk of organ or graft rejection. Overrecent years there has been a considerable improvement in the efficiencyof surgical techniques for transplanting tissues and organs such asskin, kidney, liver, heart, lung, pancreas and bone marrow. Perhaps theprincipal outstanding problem is the lack of satisfactory agents forinducing immunotolerance in the recipient to the transplanted allograftor organ. When allogeneic cells or organs are transplanted into a host(i.e., the donor and donee are different individuals from the samespecies), the host immune system is likely to mount an immune responseto foreign antigens in the transplant (host-versus-graft disease)leading to destruction of the transplanted tissue.

Uses described anywhere in this application that recite their use foranti-LUCA2 antibodies also encompass the use of other LUCA2 agonists,antagonists and modulators as described herein. In such embodiments, theLUCA2 agonists, antagonist or other non-antibody modulator issubstituted for the LUCA2 antibody in the steps described, andalterations within the scope of the ordinarily skilled practitioner aremade to tailor the method to the substituted LUCA2 modulatorycomposition.

VII. Compositions of this Invention

This invention also encompasses compositions, including pharmaceuticalcompositions, comprising anti-LUCA2 antibodies, polypeptides derivedfrom anti-LUCA2 antibodies, polynucleotides comprising sequence encodinganti-LUCA2 antibodies, and other agents as described herein. As usedherein, compositions further comprises one or more antibodies,polypeptides and/or proteins that bind to LUCA2, LUCA2 agonists,antagonists, modulators, and/or one or more polynucleotides comprisingsequences encoding one or more antibodies, polypeptides and proteinsthat bind to LUCA2.

The invention further provides for conjugates of any LUCA2 peptideagonist, antagonist or modulator, and additional chemical structuresthat support the intended function or functions of the particular LUCA2peptide agonist, antagonist or modulator. These conjugates include LUCA2peptide agonist, antagonist or modulator covalently bound to amacromolecule such as any insoluble, solid support matrix used in thediagnostic, screening or purification procedures discussed herein.Suitable matrix materials include any substance that is chemicallyinert, has high porosity and has large numbers of functional groupscapable of forming covalent linkages with peptide ligands. Examples ofmatrix materials and procedures for preparation of matrix-ligandconjugates are described in Dean et al. (eds) Affinity Chromatography: APractical Approach, IRL Press (1985); Lowe, “An Introduction to AffinityChromatography”, in Work et al. (eds) Laboratory Techniques inBiochemistry and Molecular Biology, Vol. 7, Part II, North-Holland(1979); Porath et al., “Biospecific Affinity Chromatography”, in Neurathet al. (eds), The Proteins, 3rd ed., Vol. 1, pp. 95-178 (1975); andSchott, Affinity Chromatography, Dekker (1984).

Also provided herein are conjugates of LUCA2 peptide agonist, antagonistor modulator and any reporter moiety used in the diagnostic proceduresdiscussed herein.

The LUCA2 peptide agonist, antagonist or modulator agents, polypeptidesand proteins of this invention, including anti-LUCA2 antibodies, arefurther identified and characterized by any (one or more) of thefollowing criteria: (a) ability to bind to LUCA2 (including LUCA2 oncancer cells, including but not limited to pancreatic, lung, kidney,breast, colon and prostate cancer cells); (b) ability to competitivelyinhibits preferential binding of a known anti-LUCA2 antibody to LUCA2,including the ability to preferentially bind to the same LUCA2 epitopeto which the original antibody preferentially binds; (c) ability to bindto a portion of LUCA2 that is exposed on the surface of a living cell invitro or in vivo; (d) ability to bind to a portion of LUCA2 that isexposed on the surface of living cancer cells, such as but not limitedto ovarian, prostate, pancreatic, lung, colon, or breast cancer cells;(e) ability to deliver a chemotherapeutic agent or detectable marker tocancerous cells (such as but not limited to pancreatic, lung, kidney,breast, colon and prostate cancer cells) expressing LUCA2; (f) abilityto deliver a therapeutic agent into cancerous cells (such as but notlimited to ovarian cancer cells) expressing LUCA2.

In some embodiments, the antibody of the invention is an antibody thatis produced by a host cell with a deposit number of ATCC Nos. PTA# 5068,or progeny thereof. The present invention also encompasses variousformulations of antibodies produced by these deposited hybridomas andequivalent antibodies or polypeptide fragments (e.g., Fab, Fab′,F(ab′)₂, Fv, Fc, etc.), chimeric antibodies, single chain (ScFv),mutants thereof, fusion proteins comprising an antibody portion,humanized antibodies, and any other modified configuration of any ofthese or equivalent antibodies that comprises an antigen (LUCA2),recognition site of the required specificity. The invention alsoprovides human antibodies displaying one or more of the biologicalcharacteristics of an anti-LUCA2 family member. The equivalentantibodies of the anti-LUCA2 family (including humanized antibodies andhuman antibodies), polypeptide fragments, and polypeptides comprisingany of these fragments are identified and characterized by any (one ormore) of the five criteria described above.

In some embodiments, the antibodies, polypeptides and proteins of theinvention that bind to LUCA2 are antibodies, polypeptides and proteinsthat competitively inhibit preferential binding of a herein-specifiedanti-LUCA2 antibody to LUCA2. In some embodiments, the antibodies, thepolypeptides and the proteins preferentially bind to the same epitope onLUCA2 as the antibody mu-anti-LUCA2 preferentially binds.

Accordingly, the invention provides any of the following (orcompositions, including pharmaceutical compositions, comprising any ofthe following): (a) an antibody produced by the host cell with a depositnumber identified above or its progeny; (b) a humanized form of such anantibody; (c) an antibody comprising one or more of the light chainand/or heavy chain variable regions of such an antibody; (d) a chimericantibody comprising variable regions homologous or derived from variableregions of a heavy chain and a light chain of such an antibody, andconstant regions homologous or derived from constant regions of a heavychain and a light chain of a human antibody; (e) an antibody comprisingone or more of the light chain and/or heavy chain CDRs (at least one,two, three, four, five, or six) of such an antibody; (f) an antibodycomprising a heavy and/or a light chain of such an antibody; (g) a humanantibody that is equivalent to such an antibody. A humanized form of theantibody may or may not have CDRs identical to that original antibody,or antibody produced by a host cell with a deposit number identifiedabove. Determination of CDR regions is well within the skill of the art.In some embodiments, the invention provides an antibody which comprisesat least one CDR that is substantially homologous to at least one CDR,at least two, at least three, at least four, at least 5 CDRs of anantibody produced by one of the above-identified deposited hybridomas(or, in some embodiments substantially homologous to all 6 CDRs of oneof these antibodies, or derived from one of these antibodies), orantibody produced by the host cell with a deposit number identifiedabove. Other embodiments include antibodies that have at least two,three, four, five, or six CDR(s) that are substantially homologous to atleast two, three, four, five or six CDRs of an antibody produced from ahybridoma deposited as identified herein, or derived from such anantibody. It is understood that, for purposes of this invention, bindingspecificity and/or overall activity (which may be in terms of deliveringa chemotherapeutic agent to or into cancerous cells to reduce the growthand/or proliferation of cancer cells, to induce apoptotic cell death inthe cancer cell, to delay the development of metastasis, and/or treatingpalliatively) is generally retained, although the extent of activity mayvary compared to an antibody produced by a deposited hybridoma (may begreater or lesser). The invention also provides methods of making any ofthese antibodies. Methods of making antibodies are known in the art andare described herein.

The invention also provides polypeptides comprising an amino acidsequence of the antibodies of the invention. In some embodiments, thepolypeptide comprises one or more of the light chain and/or heavy chainvariable regions of the antibody. In some embodiments, the polypeptidecomprises one or more of the light chain and heavy chain CDRs of theantibody. In some embodiments, the polypeptide comprises three CDRs ofthe light chain and/or heavy chain of the antibody. In some embodiments,the polypeptide comprises an amino acid sequence of the antibody thathas any of the following: at least 5 contiguous amino acids of asequence of the original antibody, at least 8 contiguous amino acids, atleast about 10 contiguous amino acids, at least about 15 contiguousamino acids, at least about 20 contiguous amino acids, at least about 25contiguous amino acids, at least about 30 contiguous amino acids,wherein at least 3 of the amino acids are from a variable region of theantibody. In one embodiment, the variable region is from a light chainof the original antibody. In another embodiment, the variable region isfrom a heavy chain of the antibody. In another embodiment, the 5 (ormore) contiguous amino acids are from a complementarity-determiningregion (CDR) of the antibody.

In some embodiments of this invention, cells of this invention thatexpress LUCA2, a portion of LUCA2, anti-LUCA2 antibodies or otherLUCA2-binding polypeptides of this invention are administered directlyto an individual to modulate their in vivo LUCA2 biological activity.

VIII. Methods of Using LUCA2 Modulators and Anti-LUCA2 Antibodies forTherapeutic Purposes

Monoclonal antibodies to LUCA2 may be used for therapeutic purposes inindividuals with cancer or other diseases. Therapy with anti-LUCA2antibodies can involve formation of complexes both in vitro and in vivoas described above. In one embodiment, monoclonal antibody anti-LUCA2can bind to and reduce the proliferation of cancerous cells. It isunderstood that the antibody is administered at a concentration thatpromotes binding at physiological (e.g., in vivo) conditions. In anotherembodiment, monoclonal antibodies to LUCA2 can be used for immunotherapydirected at cancerous cells of different tissues such as colon, lung,breast, prostate, pancreas, kidney and other types of cancer such assarcoma. In another embodiment, monoclonal antibody anti-LUCA2 alone canbind to and reduce cell division in the cancer cell. In anotherembodiment, monoclonal antibody anti-LUCA2 can bind to cancerous cellsand delay the development of metastasis. In yet another embodiment, anindividual with cancer is given palliative treatment with anti-LUCA2antibody. Palliative treatment of a cancer individual involves treatingor lessening the adverse symptoms of the disease, or iatrogenic symptomsresulting from other treatments given for the disease without directlyaffecting the cancer progression. This includes treatments for easing ofpain, nutritional support, sexual problems, psychological distress,depression, fatigue, psychiatric disorders, nausea, vomiting, etc.

In such situations, the anti-LUCA2 antibody may be administered withagents that enhance or direct an individual's own immune response, suchas an agent that strengthens antibody-dependent cellular cytotoxicity(ADCC).

In other embodiments, at least one fucose residue present in ananti-LUCA2 antibody is removed from the oligosaccharides of thatantibody, a modification to enhance ADCC. In similar embodiments, fucoseresidues present in an anti-LUCA2 antibody are modified to alter theircomposition to the extent required to enhance ADCC compared to theoriginal, unmodified antibody.

In yet another embodiment, anti-LUCA2 antibody be conjugated to orassociated with a radioactive molecule, toxin (e.g., calicheamicin),chemotherapeutic molecule, liposomes or other vesicles containingchemotherapeutic compounds and administered to an individual in need ofsuch treatment to target these compounds to the cancer cell containingthe antigen recognized by the antibody and thus eliminate cancerous ordiseased cells. Without being limited to any particular theory, theanti-LUCA2 antibody is internalized by the cell bearing LUCA2 at itssurface, thus delivering the conjugated moiety to the cell to induce thetherapeutic effect. In yet another embodiment, the antibody can beemployed as adjuvant therapy at the time of the surgical removal of acancer expressing the antigen in order to delay the development ofmetastasis. The antibody can also be administered before surgery(neoadjuvant therapy) in an individual with a tumor expressing theantigen in order to decrease the size of the tumor and thus enable orsimplify surgery, spare tissue during surgery, and/or decrease theresulting disfigurement.

Cell cycle dosing is contemplated in the practice of this invention. Insuch embodiments, a chemotherapeutic agent is used to synchronize thecell cycle of the tumor or other target diseased cells at apre-determined stage. Subsequently, administration of the anti-LUCA2antibody of this invention (alone or with an additional therapeuticmoiety) is made. In alternative embodiments, an anti-LUCA2 antibody isused to synchronize the cell cycle and reduce cell division prior toadministration of a second round of treatment; the second round may beadministration of an anti-LUCA2 antibody and an additional therapeuticmoiety.

Chemotherapeutic agents include radioactive molecules, toxins, alsoreferred to as cytotoxins or cytotoxic agents, which includes any agentthat is detrimental to the viability of cancerous cells, agents, andliposomes or other vesicles containing chemotherapeutic compounds.Examples of suitable chemotherapeutic agents include but are not limitedto 1-dehydrotestosterone, 5-fluorouracil decarbazine, 6-mercaptopurine,6-thioguanine, actinomycin D, adriamycin, aldesleukin, alkylatingagents, allopurinol sodium, altretamine, amifostine, anastrozole,anthramycin (AMC)), anti-mitotic agents, cis-dichlorodiamine platinum(II) (DDP) cisplatin), diamino dichloro platinum, anthracyclines,antibiotics, antimetabolites, asparaginase, BCG live (intravesical),betamethasone sodium phosphate and betamethasone acetate, bicalutamide,bleomycin sulfate, busulfan, calcium leucouorin, calicheamicin,capecitabine, carboplatin, lomustine (CCNU), carmustine (BSNU),Chlorambucil, Cisplatin, Cladribine, Colchicin, conjugated estrogens,Cyclophosphamide, Cyclothosphamide, Cytarabine, Cytarabine, cytochalasinB, Cytoxan, Dacarbazine, Dactinomycin, dactinomycin (formerlyactinomycin), daunirubicin HCL, daunorucbicin citrate, denileukindiftitox, Dexrazoxane, Dibromomannitol, dihydroxy anthracin dione,Docetaxel, dolasetron mesylate, doxorubicin HCL, dronabinol, E. coliL-asparaginase, emetine, epoetin alfa, Erwinia L-asparaginase,esterified estrogens, estradiol, estramustine phosphate sodium, ethidiumbromide, ethinyl estradiol, etidronate, etoposide citrororum factor,etoposide phosphate, filgrastim, floxuridine, fluconazole, fludarabinephosphate, fluorouracil, flutamide, folinic acid, gemcitabine HCL,glucocorticoids, goserelin acetate, gramicidin D, granisetron HCL,hydroxyurea, idarubicin HCL, ifosfamide, interferon alfa-2b, irinotecanHCL, letrozole, leucovorin calcium, leuprolide acetate, levamisole HCL,lidocaine, lomustine, maytansinoid, mechlorethamine HCL,medroxyprogesterone acetate, megestrol acetate, melphalan HCL,mercaptipurine, mesna, methotrexate, methyltestosterone, mithramycin,mitomycin C, mitotane, mitoxantrone, nilutamide, octreotide acetate,ondansetron HCL, paclitaxel, pamidronate disodium, pentostatin,pilocarpine HCL, plimycin, polifeprosan 20 with carmustine implant,porfimer sodium, procaine, procarbazine HCL, propranolol, rituximab,sargramostim, streptozotocin, tamoxifen, taxol, teniposide, tenoposide,testolactone, tetracaine, thioepa chlorambucil, thioguanine, thiotepa,topotecan HCL, toremifene citrate, trastuzumab, tretinoin, valrubicin,vinblastine sulfate, vincristine sulfate, and vinorelbine tartrate.

In a preferred embodiment, the cytotoxin is especially effective individing or rapidly dividing cells, such that non-dividing cells arerelatively spared from the toxic effects.

The antibodies of the invention can be internalized within the diseasedor carcinoma cells to which they bind and are therefore particularlyuseful for therapeutic applications, for example, delivering into thecells toxins that need to be internalized for their adverse activity.Examples of such toxins include, but not limited to, saporin,calicheamicin, auristatin, and maytansinoid.

The antibodies or polypeptides of the invention can be associated(including conjugated or linked) to a radioactive molecule, a toxin, orother therapeutic agents, or to liposomes or other vesicles containingtherapeutic agents covalently or non-covalently, directly or indirectly.The antibody may be linked to the radioactive molecule, the toxin, orthe chemotherapeutic molecule at any location along the antibody so longas the antibody is able to bind its target LUCA2.

A toxin or a chemotherapeutic agent may be coupled (e.g., covalentlybonded) to a suitable monoclonal antibody either directly or indirectly(e.g., via a linker group, or, alternatively, via a linking moleculewith appropriate attachment sites, such as a platform molecule asdescribed in U.S. Pat. No. 5,552,391). The toxin and chemotherapeuticagent of the present invention can be coupled directly to the particulartargeting proteins using methods known in the art. For example, a directreaction between an agent and an antibody is possible when eachpossesses a substituent capable of reacting with the other. For example,a nucleophilic group, such as an amino or sulfhydryl group, on one maybe capable of reacting with a carbonyl-containing group, such as ananhydride or an acid halide, or with an alkyl group containing a goodleaving group (e.g., a halide) on the other.

The antibodies or polypeptides can also be linked to a chemotherapeuticagent via a microcarrier. Microcarrier refers to a biodegradable or anon-biodegradable particle which is insoluble in water and which has asize of less than about 150, 120 or 100 mm in size, more commonly lessthan about 50-60 μm, preferably less than about 10, 5, 2.5, 2 or 1.5 μm.Microcarriers include “nanocarriers”, which are microcarriers have asize of less than about 1 μm, preferably less than about 500 nm. Suchparticles are known in the art. Solid phase microcarriers may beparticles formed from biocompatible naturally occurring polymers,synthetic polymers or synthetic copolymers, which may include or excludemicrocarriers formed from agarose or cross-linked agarose, as well asother biodegradable materials known in the art. Biodegradable solidphase microcarriers may be formed from polymers which are degradable(e.g., poly(lactic acid), poly(glycolic acid) and copolymers thereof) orerodible (e.g., poly(ortho esters such as3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane (DETOSU) orpoly(anhydrides), such as poly(anhydrides) of sebacic acid) undermammalian physiological conditions. Microcarriers may also be liquidphase (e.g., oil or lipid based), such liposomes, iscoms(immune-stimulating complexes, which are stable complexes ofcholesterol, and phospholipid, adjuvant-active saponin) without antigen,or droplets or micelles found in oil-in-water or water-in-oil emulsions,provided the liquid phase microcarriers are biodegradable. Biodegradableliquid phase microcarriers typically incorporate a biodegradable oil, anumber of which are known in the art, including squalene and vegetableoils. Microcarriers are typically spherical in shape, but microcarriersthat deviate from spherical shape are also acceptable (e.g., ellipsoid,rod-shaped, etc.). Due to their insoluble nature (with respect towater), microcarriers are filterable from water and water-based(aqueous) solutions.

The antibody or polypeptide conjugates of the present invention mayinclude a bifunctional linker that contains both a group capable ofcoupling to a toxic agent or chemotherapeutic agent and a group capableof coupling to the antibody. A linker can function as a spacer todistance an antibody from an agent in order to avoid interference withbinding capabilities. A linker can be cleavable or non-cleavable. Alinker can also serve to increase the chemical reactivity of asubstituent on an agent or an antibody, and thus increase the couplingefficiency. An increase in chemical reactivity may also facilitate theuse of agents, or functional groups on agents, which otherwise would notbe possible. The bifunctional linker can be coupled to the antibody bymeans that are known in the art. For example, a linker containing anactive ester moiety, such as an N-hydroxysuccinimide ester, can be usedfor coupling to lysine residues in the antibody via an amide linkage. Inanother example, a linker containing a nucleophilic amine or hydrazineresidue can be coupled to aldehyde groups produced by glycolyticoxidation of antibody carbohydrate residues. In addition to these directmethods of coupling, the linker can be indirectly coupled to theantibody by means of an intermediate carrier such as an aminodextran. Inthese embodiments the modified linkage is via either lysine,carbohydrate, or an intermediate carrier. In one embodiment, the linkeris coupled site-selectively to free thiol residues in the protein.Moieties that are suitable for selective coupling to thiol groups onproteins are well known in the art. Examples include disulfidecompounds, α-halocarbonyl and α-halocarboxyl compounds, and maleimides.When a nucleophilic amine function is present in the same molecule as anα-halo carbonyl or carboxyl group the potential exists for cyclizationto occur via intramolecular alkylation of the amine. Methods to preventthis problem are well known to one of ordinary skill in the art, forexample by preparation of molecules in which the amine and α-halofunctions are separated by inflexible groups, such as aryl groups ortrans-alkenes, that make the undesired cyclization stereochemicallydisfavored. See, for example, U.S. Pat. No. 6,441,163 for preparation ofconjugates of maytansinoids and antibody via a disulfide moiety.

One of the cleavable linkers that can be used for the preparation ofantibody-drug conjugates is an acid-labile linker based on cis-aconiticacid that takes advantage of the acidic environment of differentintracellular compartments such as the endosomes encountered duringreceptor mediated endocytosis and the lysosomes. See, for example, Shenet al., Biochem. Biophys. Res. Commun. 102:1048-1054 (1981) for thepreparation of conjugates of daunorubicin with macromolecular carriers;Yang et al., J. Natl. Canc. Inst. 80:1154-1159 (1988) for thepreparation of conjugates of daunorubicin to an anti-melanoma antibody;Dillman et al., Cancer Res. 48:6097-6102 (1988) for using an acid-labilelinker in a similar fashion to prepare conjugates of daunorubicin withan anti-T cell antibody; Trouet et al., Proc. Natl. Acad. Sci.79:626-629 (1982) for linking daunorubicin to an antibody via a peptidespacer arm.

An antibody (or polypeptide) of this invention may be conjugated(linked) to a radioactive molecule by any method known to the art. For adiscussion of methods for radiolabeling antibody see “Cancer Therapywith Monoclonal AntibodiesT”, D. M. Goldenberg ed. (CRC Press, BocaRaton, 1995).

Alternatively, an antibody can be conjugated to a second antibody toform an antibody heteroconjugate as described by Segal in U.S. Pat. No.4,676,980. The formation of cross-linked antibodies can target theimmune system to specific types of cells, for example, cancer ordiseased cells expressing LUCA2.

This invention also provides methods of delaying development ofmetastasis in an individual with cancer (including, but not limited to,prostate, lung, breast, ovarian, pancreatic, or colon cancer) using ananti-LUCA2 antibody or other embodiments that bind to LUCA2 linked to achemotherapeutic agent. In some embodiments, the antibody is a humanizedor chimeric form of a non-human anti-LUCA2 antibody.

In yet another embodiment, the antibody can be employed as adjuvanttherapy at the time of the surgical removal of a cancer expressing theantigen in order to delay the development of metastasis. The antibody orantibody associated with a chemotherapeutic agent can also beadministered before surgery (neoadjuvant therapy) in an individual witha tumor expressing the antigen in order to decrease the size of thetumor and thus enable or simplify surgery, spare tissue during surgery,and/or decrease the resulting disfigurement.

In yet another embodiment, any of the LUCA2 binding embodimentsdescribed herein can bind to LUCA2-expressing cancerous cells andinduces an active immune response against the cancerous cells expressingLUCA2. In some cases, the active immune response can cause the death ofthe cancerous cells (e.g., antibody binding to cancer cells inducingapoptotic cell death), or inhibit the growth (e.g., block cells cycleprogression) of the cancerous cells. In other cases, any of the novelantibodies described herein can bind to cancerous cells and antibodydependent cellular cytotoxicity (ADCC) can eliminate cancerous cells towhich anti-LUCA2 binds. Accordingly, the invention provides methods ofstimulating an immune response comprising administering any of thecompositions described herein.

In some cases, antibody binding can also activate both cellular andhumoral immune responses and recruit more natural killer cells orincreased production of cytokines (e.g., IL-2, IFN-g, IL-12, TNF-a,TNF-b, etc.) that further activate an individual's immune system todestroy cancerous cells. In yet another embodiment, anti-LUCA2antibodies can bind to cancerous cells, and macrophages or otherphagocytic cell can opsonize the cancerous cells.

In other cases, antibody binding can block cellular immune responses andalter the response of immune cell activation. For example, anti-LUCA2antibodies can bind to MAC-1 (CD11b/CD18) on the cell surface of normalhuman neutrophils. Such binding can block normal MAC-1 interactions withother immune cells such as dendritic cells and alter antigen-presentingprocesses. This effect demonstrates the applicability of the methods oftreatment and diagnosis claimed herein as they apply to immunologicaldisorders, inflammatory processes, and neurological functions.

Various formulations of anti-LUCA2 antibodies or fragments thereof maybe used for administration. In some embodiments, anti-LUCA2 antibodiesor fragments thereof may be administered neat. In addition to thepharmacologically active agent, the compositions of the presentinvention may contain suitable pharmaceutically acceptable carrierscomprising excipients and auxiliaries that are well known in the art andare relatively inert substances that facilitate administration of apharmacologically effective substance or which facilitate processing ofthe active compounds into preparations that can be used pharmaceuticallyfor delivery to the site of action. For example, an excipient can giveform or consistency, or act as a diluent. Suitable excipients includebut are not limited to stabilizing agents, wetting and emulsifyingagents, salts for varying osmolarity, encapsulating agents, buffers, andskin penetration enhancers.

Suitable formulations for parenteral administration include aqueoussolutions of the active compounds in water-soluble form, for example,water-soluble salts. In addition, suspensions of the active compounds asappropriate for oily injection suspensions may be administered. Suitablelipophilic solvents or vehicles include fatty oils, for example, sesameoil, or synthetic fatty acid esters, for example, ethyl oleate ortriglycerides. Aqueous injection suspensions may contain substances thatincrease the viscosity of the suspension and include, for example,sodium carboxymethyl cellulose, sorbitol, and/or dextran. Optionally,the suspension may also contain stabilizers. Liposomes can also be usedto encapsulate the agent for delivery into the cell.

The pharmaceutical formulation for systemic administration according tothe invention may be formulated for enteral, parenteral or topicaladministration. Indeed, all three types of formulation may be usedsimultaneously to achieve systemic administration of the activeingredient. Excipients as well as formulations for parenteral andnonparenteral drug delivery are set forth in Remington, The Science andPractice of Pharmacy 20th Ed. Mack Publishing (2000).

Suitable formulations for oral administration include hard or softgelatin capsules, pills, tablets, including coated tablets, elixirs,suspensions, syrups or inhalations and controlled, release formsthereof.

Generally, these agents are formulated for administration by injection(e.g., intraperitoneally, intravenously, subcutaneously,intramuscularly, etc.), although other forms of administration (e.g.,oral, mucosal, etc) can be also used. Accordingly, anti-LUCA2 antibodiesare preferably combined with pharmaceutically acceptable vehicles suchas saline, Ringer's solution, dextrose solution, and the like.

The particular dosage regimen, i.e., dose, timing and repetition, willdepend on the particular individual and that individual's medicalhistory. Generally, a dose of at least about 100 ug/kg body weight, morepreferably at least about 250 ug/kg body weight, even more preferably atleast about 750 ug/kg body weight, even more preferably at least about 3mg/kg body weight, even more preferably at least about 5 mg/kg bodyweight, even more preferably at least about 10 mg/kg body weight isadministered.

Empirical considerations, such as the half-life, generally willcontribute to the determination of the dosage. Antibodies, which arecompatible with the human immune system, such as humanized antibodies orfully human antibodies, may be used to prolong half-life of the antibodyand to prevent the antibody being attacked by the host's immune system.Frequency of administration may be determined and adjusted over thecourse of therapy, and is based on reducing the number of cancerouscells, maintaining the reduction of cancerous cells, reducing theproliferation of cancerous cells, or delaying the development ofmetastasis. Alternatively, sustained continuous release formulations ofanti-LUCA2 antibodies may be appropriate. Various formulations anddevices for achieving sustained release are known in the art.

In one embodiment, dosages for anti-LUCA2 antibodies may be determinedempirically in individuals who have been given one or moreadministration(s). Individuals are given incremental dosages of ananti-LUCA2 antibody. To assess efficacy of anti-LUCA2 antibodies, amarker of the specific cancer disease state can be followed. Theseinclude direct measurements of tumor size via palpation or visualobservation, indirect measurement of tumor size by x-ray or otherimaging techniques; an improvement as assessed by direct tumor biopsyand microscopic examination of the tumor sample; the measurement of anindirect tumor marker (e.g., PSA for prostate cancer), a decrease inpain or paralysis; improved speech, vision, breathing or otherdisability associated with the tumor; increased appetite; or an increasein quality of life as measured by accepted tests or prolongation ofsurvival. It will be apparent to one of skill in the art that the dosagewill vary depending on the individual, the type of cancer, the stage ofcancer, whether the cancer has begun to metastasize to other location inthe individual, and the past and concurrent treatments being used.

Other formulations include suitable delivery forms known in the artincluding, but not limited to, carriers such as liposomes. See, forexample, Mahato et al. (1997) Pharm. Res. 14:853-859. Liposomalpreparations include, but are not limited to, cytofectins, multilamellarvesicles and unilamellar vesicles.

In some embodiments, more than one antibody may be present. Theantibodies can be monoclonal or polyclonal. Such compositions maycontain at least one, at least two, at least three, at least four, atleast five different antibodies that are reactive against carcinomas,adenocarcinomas, sarcomas, or adenosarcomas. Anti-LUCA2 antibody can beadmixed with one or more antibodies reactive against carcinomas,adenocarcinomas, sarcomas, or adenosarcomas in organs including but notlimited to ovary, breast, lung, prostate, colon, kidney, skin, thyroid,bone, upper digestive tract, and pancreas. In one embodiment, a mixtureof different anti-LUCA2 antibodies is used. A mixture of antibodies, asthey are often denoted in the art, may be particularly useful intreating a broader range of population of individuals.

The following examples are provided to illustrate, but not to limit, theinvention.

EXAMPLES Example 1 Preparation of Human Lung Carcinoma Cells as anImmunogen

Tissue from a human lung adenocarcinoma was rinsed briefly in sterilephosphate buffered saline (PBS) containing 100 μg/ml gentamycin. Therinsed tissue was then placed in a 100 mm tissue culture dish and mincedinto small (less than 1 mm pieces) with scissors. 5 ml F12/DME (50:50)medium containing 100 μg/ml gentamycin and 200 μl collagenase-dispase(10% wt/vl in PBS with 10% soybean trypsin inhibitor) was added to theminced tissue pieces. The tissue pieces were briefly resuspended in thisdissociation medium and then incubated at 37° C. for 30 minutes withrepeated pipetting every 5 minutes to loosen the cell aggregates. Theenzymatic activity was stopped when small aggregates of 10-20 cellsappeared dissociated from the tissue. The suspension was placed in a 15ml conical centrifuge tube and the volume was adjusted to 10 ml withF12/DME medium and centrifuged for 4 minutes at 900 rpm. The supernatantwas aspirated and the pellet was resuspended in F12/DME (1 mM Ca²⁺)growth medium with the following nutrient supplements: Insulin 10 μg/ml,Transferrin 10 μg/ml, Epidermal growth factor (EGF) 5 ng/ml,Triiodothyronine (T3) 10⁻¹²M, Ethanolamine 10⁻⁶M, Phosphoethanolamine10M, Selenium 2.5×10⁻⁸M, Progesterone 10⁻⁸M, Hydrocortisone 10⁻⁹M,Forskolin 5 μM, Porcine pituitary extract (PPE) 5 μl/ml, Gentamycin 100μg/ml, and Sterile filtered conditioned media from fetal lung cellcultures, 20% v/v.

Aliquots of the dissociated tissue were resuspended in a total of 10 mleach and then plated into five 100 mm fibronectin-coated dishes. Thecultures were largely mixed cell types, but in the absence of serum,epithelial cells were maintained while most of the non-epithelial cellsdid not survive or grow. Time-lapse videography showed some of thecolonies contain ciliated epithelial cells. These cultures were grown inDME/F12 basal medium, supplemented with the following nutrients: Insulin10 μg/ml, Epidermal growth factor (EGF) 5 ng/ml, Selenium 2.5×10⁻⁸M,Hydrocortisone 10⁻⁹M, and Porcine pituitary extract (PPE) 5 μl/ml.

To harvest the cells, the cell monolayers were rinsed once with calcium-and magnesium-free Hanks saline solution, incubated in 10 mM EDTA inHanks saline solution at 37 C for 15 minutes. The cells were detachedfrom the culture surface by gentle pipetting. The cell suspension waspelleted by centrifugation at 1000×g for 5 minutes. The supernatant wasremoved and cells were resuspended in serum-free DME/F12 medium withnon-denaturing adjuvant as appropriate.

Example 2 Generation of Monoclonal Antibodies

A non-denaturing adjuvant (Ribi, R730, Corixa, Hamilton Mont.) wasrehydrated to 2 ml in phosphate buffered saline. 100 μl of thisrehydrated adjuvant was then gently mixed with some of the cell pelletfrom Example 1 to be used for immunization. Approximately 10⁶ human lungcarcinoma cells per mouse were injected into Balb/c mice via footpad,approximately once or twice a week. The precise immunization schedule isas follows: Day zero, immunization plus Ribi. Day 3, immunization plusRibi. Day 7, immunization plus Ribi. Day 24, immunization minus Ribi.Day 29, immunization minus Ribi. Day 32, immunization minus Ribi. Day36, immunization minus Ribi. Day 44, immunization minus Ribi. Day 51,immunization minus Ribi. Day 69, bleed for titer test. Day 71.immunization plus Ribi. Day 74, immunization plus Ribi. Day 81,immunization plus Ribi. Day 91, pre-fusion boost (no Ribi). Day 104,harvest nodes for fusion.

At Day 69, a drop of blood was drawn from the tail of each immunizedanimal to test the titer of antibodies against the immunizing cells orcell line using FACS analysis. When the titer reached at least 1:2000,the mice were sacrificed using CO₂ followed by cervical dislocation.Lymph nodes were harvested for hybridoma preparation.

Lymphocytes from mice were fused with the mouse myeloma line X63-Ag8.653using 35% polyethylene glycol 4000. On day 10 following the fusion, thehybridoma supernatants were screened for the presence of human fetalkidney cells-specific monoclonal antibodies by fluorescence activatedcell sorting (FACS). Conditioned medium from each hybridoma wasincubated for 30 minutes with an aliquot of the immunizing cells or cellline. After incubation, the cell samples were washed, resuspended in 0.1ml diluent and incubated with 1 μg/ml of FITC conjugated F(ab′)₂fragment of goat anti-mouse IgG for 30 min at 4° C. The cells werewashed, resuspended in 0.2 ml FACS diluent and analyzed using a FACScancell analyzer (Becton Dickinson; San Jose, Calif.). Hybridoma cloneswere selected for further expansion, cloning, and characterization basedon their binding to the surface of immunizing cells or cell line byFACS. A hybridoma making a monoclonal antibody designated mu-anti-LUCA2which binds an antigen designated LUCA2 was selected. The hybridomamaking mu-anti-LUCA2 antibodies was further expanded in growth mediumsuitable for sustaining hybridoma growth and antibody purification.

Example 3 Purification of Anti-LUCA2 Antibodies, Including Mu-Anti-LUCA2

Human lung carcinoma cells were detached from tissue culture flasks inthe presence of 10.0 mM EDTA, centrifuged at 1400 rpm for 5 minutes andresuspended in PBS containing 1% BSA and 2 mM EDTA (FACS diluent). Thecells were counted and adjusted to 10⁷ cells/ml. About 0.1 ml of cellswere incubated with 100 μl FACS diluent for 30 minutes at 37° C.Monoclonal antibodies that bind to human lung carcinoma cells werepurified from tissue culture supernatant using protein-G affinitychromatography. The tissue culture supernatant may be first passedthrough a bovine IgG column to remove excess bovine IgG in thesupernatant if desired. The following materials were used for theantibody purification process: hybridoma tissue culture supernatant,Immunopure (G) IgG binding buffer (Pierce #21011 Rockford, Ill.),Immunopure IgG Elution Buffer (Pierce #21009), concentrated HCl (foradjusting pH), Corning 1 liter PES (polyether sulfone), 0.22 μm filter(Corning #431098, Corning, N.Y.), Amersham Pharmacia AKTA ExplorerSystem (Amersham Biosciences, Piscataway, N.J.), Protein-G Sepharose 4Fast Flow (Amersham Biosciences #17-0618-03), Stripping bufferconsisting of 3M Potassium thiocyanate/50 mM Tris pH 7.8, and PBS(phosphate buffered saline), 3M Tris pH 9.0.

To purify the mouse anti-human LUCA2 antibody referred to herein asmu-anti-LUCA2, the volume of the supernatant was measured and an equalvolume of binding buffer was added to the supernatant. The mixture wasallowed to equilibrate to room temperature. The supernatant wasclarified by passage through a 0.22 μm filter. The supernatant wasloaded onto a protein-G Sepharose column using the AKTA Explorer system(Amersham Biosciences) and then washed with 5-10 column volumes ofbinding buffer. The monoclonal antibody was eluted with the elutionbuffer, and fractions were collected. The fractions were neutralizedupon elution with the addition of 3M Tris, pH 9.0 to empty tubes ( 1/60volume of the fractions). The peak fractions containing the monoclonalantibody were pooled. The pooled samples was injected into a pre-wettedslidealyzer cassette (10,000 MW cutoff; Pierce #66810) and dialyzed in1×PBS at 4° C. (with 3 buffer changes of at least 4 hours of dialysisper change). The purified monoclonal antibody was sterile filtered (0.2μm Acrodisc) and stored at 2-8° C.

A sample of purified antibody is taken for determination ofconcentration by UV absorbance (A₂₈₀) and SDS-polyacrylimide gelelectrophoresis (SDS-PAGE). SDS-PAGE is run under both non-reducing andreducing conditions for analysis of molecular weight, identification ofthe typical banding pattern of monoclonal antibodies and assessment ofpurity.

After purification of the mu-anti-LUCA2 monoclonal antibody from thehybridoma supernatant, it was re-tested for binding to human fetalkidney cells. The cell samples were prepared as described above andincubated with the purified antibody at various concentrations. Afterincubation the cells were washed, resuspended in 0.1 ml diluent andincubated with 1 μg of FITC conjugated F(ab)'2 fragment of goatanti-mouse IgG for 30 minutes at 4° C. The cells were washed,resuspended in 0.5 ml FACS diluent and analyzed using a FACScan cellsorter (Becton Dickinson, San Jose, Calif.). A shift to the right on theFACScan histogram indicated that the purified antibody still bound tothe immunizing cells.

In other experiments, the binding of the mu-anti-LUCA2 antibody to LUCA2was tested using live cell ELISA. The following method was used,although other methods commonly known in the field are applicable. Cells(HT-29, SKOV3, SKMES-1, SW480, SKBR-3, and HPAFII) were grown in 10%fetal bovine serum (FBS) containing media to confluency on tissueculture treated 96-well plates (Falcon). Cells were washed with PBS andthen incubated with 50 μl of desired antibodies at a desiredconcentration in Hank's Balanced Salt Solution (HBSS) containing 1% BSAand 0.1% sodium azide for 1 hour at room temperature. The cells werethen washed three times with 1000 per well of HBSS before incubatingwith horseradish peroxidase (HRP) secondary antibody (500 per welldiluted in HBSS) for 30 minutes at room temperature. The cells werefinally washed three times with HBSS and the color change substrate (TMBsubstrate, KPL) was added to each well at 100 μl per well. The colorchange reaction was stopped with the addition of 100 μl per well of 1Mphosphoric acid. The plates were then read at O.D. 450 nm.

Example 4 Western Blot Analysis of LUCA2 Expression in Cancer Cell LinesColo205 and HT-29

Colorectal adenocarcinoma cell lines Colo205 and HT-29 were grown toconfluency on 175 cm² culture dishes. The confluent monolayer was washedthree times with Hank's Balanced Salt Solution (HBSS+ containing nosodium bicarbonate or phenol red; buffered with 10 mM HEPES, pH 7.4;Sigma Chemicals) and biotinylated with 200 μg of sulfo-NHS-LC-biotin(Pierce Endogen) for 30 minutes at room temperature. The cells were thenwashed with HBSS+ containing 0.1M Tris, pH 7.4 (Sigma Chemicals) andincubated in HBSS+ containing 0.1M Tris, pH 7.4 for 15 minutes at roomtemperature. The cells were finally washed three times with HBSS+ andlysed by incubation for 5 minutes, on ice, in lysis buffer (HBSS+ with2% Triton X-100, 2 mM PMSF, 0.1% sodium azide, and 1 tablet per 5 mllysis buffer of EDTA free complete mini-protease cocktail (RocheMolecular Biochemicals)).

Cells were scraped in lysis buffer and lysates collected. Lysates werecentrifuged at 14,000×g for one hour at 4° C. The clarified lysate wasthen pre-cleared for 2 hours at 4° C. with 5 μl of human IgG conjugated(1 mg/ml) CNBr 4 MB Sepharose beads (Amersham Pharmacia). Human IgGbeads were centrifuged and removed, and then the pre-cleared lysate wasthen incubated with monoclonal antibody mu-anti-LUCA2 conjugated to CNBr4 MB sepharose beads (conjugated at 1 mg/ml) for 2 hours at 4° C. Themu-anti-LUCA2 beads were centrifuged and removed after the 2-hourincubation. Both the human IgG and the mu-anti-LUCA2 beads wereindividually washed three times with 1 ml of lysis buffer and thenwashed three times with 1 ml HBSS+. The washed beads were eluted by theaddition of 30 μl of SDS-PAGE sample buffer and boiling at 99° C. for 5minutes.

The samples were then resolved on a 4-20% Novex gradient gel(Invitrogen), and transferred onto 0.2 μm nitrocellulose membrane(Invitrogen) and visualized by western blotting with 5 μg/blot ofmu-anti-LUCA2.

For western blotting with mu-anti-LUCA2 the nitrocellulose was similarlyblocked for 1 hour in blocking buffer. The nitrocellulose was thenincubated in a heat sealed plastic pouch containing 1 ml of 5 μg/mlmu-anti-LUCA2 diluted in blocking buffer. The nitrocellulose was washed3 times with TBST before incubation with 10 ml of 1 μg/mlHRP conjugateddonkey anti-mouse IgG (heavy and light chain specific, cross adsorbedagainst bovine, chicken, goat, guinea pig, Syrian hamsters, horse,human, rabbit, sheep serum proteins; Jackson Immunoresearch Cat.#709-035-149) for 1 hour at room temperature. The nitrocellulose wasfinally washed three times with TBST and visualized by ECL+(Amersham).Results using this protocol and mu-anti-LUCA2 antibodies show a doubletof high molecular weight bands at −150 kDa and −210 kDa under reducingconditions. An example of these results is shown in FIG. 1, with arrowspointing to the specific high molecular weight doublet that is in theColo205 and HT-29 lanes, but absent from the IgG control lanes.

Example 5 Immunohistochemistry Methods

Frozen tissue samples from cancer patients were embedded in OCT compoundand quick-frozen in isopentane with dry ice. Cryosections were cut witha Leica 3050 CM mictrotome at thickness of 8-10 μM and thaw-mounted onSuperFrost Plus slides (VWR #48311-703). The sections were fixed with75% acetone/25% ethanol at 10° C. and allowed to air-dry 2-4 hours atroom temperature. The fixed sections were stored at −80° C. until use.

For immunohistochemistry, the tissue sections were retrieved washed inTris buffered 0.05% Tween (TB-T) and blocked in blocking buffer (TB-T,normal goat serum and 100 μg/ml avidin) for 30 minutes at roomtemperature. The slides were then incubated with the mu-anti-LUCA2 andcontrol monoclonal antibodies diluted in blocking buffer (1 μg/ml) for60-90 minutes at room temperature. The sections were then washed threetimes with the blocking buffer. The bound monoclonal antibodies weredetected with a goat anti-mouse IgG+IgM (H+L)F(ab′)²-peroxidaseconjugates and the peroxidase substrate diaminobenzidine (1 mg/ml, Sigmacat. No. D 5637) in 0.1 M sodium acetate buffer pH 5.05 and 0.003%hydrogen peroxide (Sigma cat. No. H1009). The stained slides werecounter-stained with hematoxylin and examined under Nikon microscope.

In some cases, paraffin embedded formaldehyde-fixed tissues were usedfor immunohistochemistry after appropriate antigen retrieval methodswere employed. One such antigen retrieval method is described in Manghamand Isaacson, Histopathology 35:129-33 (1999). Other methods of antigenretrieval and/or detection may be used by one skilled in the art.Results from similar experiments performed using frozen tissues or,where appropriate, fixed tissue with antigen retrieval and polyMICAdetection were performed. The binding of anti-LUCA2 antibody to avariety of normal and cancer tissues was assessed. In all cases,antibody binding in control fixed tissues was correlated with that offrozen tissues. The results from frozen tissues were only used if thetwo did not match in the controls.

For convenience, a summary of the combined results of severalexperiments using frozen surgical tissue from different sources is shownbelow in Table 1 and Table 2.

TABLE 1 Distribution of LUCA2 in normal human tissues Tissue TypeResults Skin some endothelial staining Liver Scattered staining Kidney2+ staining in tubules Lung Scattered staining on macrophages Colon 2+on mucosa Duodenum Negative Stomach 3+ gastric glandular cells BreastNegative Ovary 2-3+ on cyst lining Prostate 2-3+ focal staining onepithelial cells

TABLE 2 Distribution of LUCA2 in human tumor tissues Tissue Type ResultsColon Negative to −/+ Prostate Negative to 1+ focal staining Pancreas 1+to 2+ on tumor Endometrium +/− staining on tumor Kidney 1+ to 2+staining on tumor Lung +/− to 2+ on tumor

Example 6 Immunocytochemistry Results

Monoclonal antibody mu-anti-LUCA2 was used to test reactivity withvarious cell lines from different types of tissues. The results werescored as ‘+’ for weak positive staining, ‘++’ for moderate positivestaining, ‘+++’ for strong positive staining and ‘−’ for negativestaining.

Immunohistochemistry results were obtained using CellArray™ technology,as described in WO 01/43869. Cells from different established cell lineswere removed from the growth surface without using proteases, packed andembedded in OCT compound. The cells were frozen and sectioned, thenstained using a standard IHC protocol.

Results of the binding of the mu-anti-LUCA2 antibody to variousestablished human normal and tumor cell lines are compiled forconvenience in Table 3. The experiments represented in Table 3 includeLive-cell ELISA and CellArray™ binding experiments using the methodsdescribed herein.

TABLE 3 Immunocytochemistry results Reactivity Reactivity Live Cell lineATCC# Organ Cell Type Cell Array Cell ELISA HMEC CC-2251 * Breast Normalmammary − epithelial HuVEC Primary Endothelial Normal human adult −cells BT474 HTB-20 Breast Ductal carcinoma +++ MCF7 HTB-22 BreastAdenocarcinoma +++ MDA175 HB-25 Breast Ductal carcinoma +++ MDA361 HB-27Breast Adenocarcinoma +++ SK-BR-3 HTB-30 Breast Adenocarcinoma ++ − 9979RAVEN Lung Lung cancer line +++ A549 CCL-185 Lung Carcinoma +′/′−′ CA130RAVEN Lung Small cell carcinoma +++ CaLu3 HTB-55 Lung Adenocarcinoma +++SKMES1 HTB-58 Lung Squamous carcinoma +′/′−′ ES-2 CRL-1978 OvaryCarcinoma − SKOV3 HTB-77 Ovary Adenocarcinoma ++ − 9926 RAVEN PancreasAdenocarcinoma +++ AsPC-1 CRL-1682 Pancreas Adenocarcinoma +′/′−′ HPAFIICRL-1997 Pancreas Adenocarcinoma − ++ Hs700T HTB-147 PancreasAdenocarcinoma +++ Colo205 CCL-222 Colon Ascites colorectal +++adenocarcinoma HT-29 HTB-38 Colon Colorectal ++ + adenocarcinoma SW480CCL-228 Colon Colorectal +++ + adenocarcinoma SW948 CCL-237 ColonColorectal +++ adenocarcinoma 293 CRL-1573 Kidney Transformed with −adenovirus5 DNA 786-O CRL-1932 Kidney Renal Cell Carcinoma ++ A498HTB-44 Kidney Carcinoma ++ Caki2 HTB-47 Kidney Clear cell carcinoma +++Cos 7 CRL-1651 Kidney SV40 transformed +′/′−′ (African Green Monkey)RL65 CRL-10345 Lung (Rat) − SVT2 CCL-163.1 Embryo Fibroblast; SV40 −(Mouse) transformed 22RV1 CRL-2505 Prostate Carcinoma − DU145 HTB-81Prostate Adenocarcinoma ++ LNCaP CRL-1740 Prostate Carcinoma ++ PC3CRL-1435 Prostate Adenocarcinoma − TDH-1 RAVEN Prostate Prostate cancerline ++ Hs746T HTB-135 Stomach Carcinoma − NCI-N87 CRL-5822 StomachCarcinoma +++ * CC-2251 BioWhittaker

Monoclonal antibody mu-anti-LUCA2 was used to test reactivity withglioma-derived cell lines. Immunocytochemistry results were obtainedusing similar protocol as described above for the CellArray™ technology.The glioma-derived cell lines were removed from the growth surfacewithout using proteases, packed and embedded in OCT compound. The cellswere frozen and sectioned, then stained using a standard IHC protocol.Mu-anti-LUCA2 was positive (+/− to 3+) on 7/25 glioma-derived cell linesscreened.

Example 7 Characterization of the Epitope to which Mu-Anti-LUCA2 BindsUsing Tandem Mass Spectrometry (MS/MS)

The epitope to which mu-anti-LUCA2 binds was isolated as described inExample 4 and subjected to Tandem mass spectroscopy according to themethod of Kane et al., 2002. Proteins were separated by SDS-PAGE, andthe gel was stained with the colloidal Coomassie Blue reagent(Invitrogen). Proteins of interest were digested in the gel withtrypsin. The tryptic peptides were sequenced by microcapillary liquidchromatography MS/MS on an ion trap mass spectrometer (Thermo-FinniganLCDQ DECA XP), as described in Wu et al., 2000.

Alternatively, other well-known methods of mass-spectrometry. such asMALDI mass spectrometry, can also be used in the practice of thisinvention.

The results from the mass spectrometry experiments indicated thatmu-anti-LUCA2 specific bands consisted of various proteins, which isconsistent with a carbohydrate epitope.

Example 8 Other Characterization Experiments to Identify LUCA2

To further characterize LUCA2, normal human neutrophils were used todetermine LUCA2 expression. Normal human neutrophils were isolated fromwhole blood using ficoll-dextran sedimentation (GE Healthcare). Isolatedneutrophils were lysed and the cell lysates were immunoprecipitated witha commercial CD11b antibody (R&D Systems). The protein was resolvedusing SDS-PAGE and western blot using LUCA2 antibodies were performed. ALUCA2 specific band was observed at 170 kDa, which corresponds to themolecular weight of CD11b.

To examine the carbohydrate properties of proteins containing LUCA2,LUCA2 was purified from normal human neutrophils (the 170 kDa CD11bprotein) and subjected to deglycosylation using, N-glycanase,S-glycanase O-glycanase and combinations of these three glycanases(Prozyme, Calif.). Methods following the manufacturer's protocols wereused, although other methods commonly known in the art are alsoapplicable. The 170 kDa protein preparation treated with N-glycanaseshowed no mu-anti-LUCA2 activity when resolved on a western blot usingmu-anti-LUCA2 (FIG. 2, lane 2). Similarly, the 170 kDa proteinpreparation treated with N-glycanase+S-glycanase showed no mu-anti-LUCA2activity when resolved on a western blot using mu-anti-LUCA2 (FIG. 2,lane 3). Treatment with O-glycanase did not seem to affect mu-anti-LUCA2activity as compared with no glycanase treatment when resolved on awestern blot using mu-anti-LUCA2 (no glycanase treatment: FIG. 2, Lane1; O-glycanase treatment: FIG. 2, Lane 4). The 170 kDa proteinpreparation treated with all three glycanases showed no mu-anti-LUCA2activity (FIG. 2, Lane 5). These results indicate that LUCA2 is likelyto be a N-linked carbohydrate epitope that is present on a number ofproteins including CD11b.

To further characterize the carbohydrate epitope that mu-anti-LUCA2recognizes, ELISA for mu-anti-LUCA2 binding to Lewis B (LNFP-I), Lewis A(LNFP-II), Lewis X (LNFP-III) and Lacto-N-difucohexaose I (LNDFP-I) wasperformed. Commonly known methods of ELISA are applicable. Briefly, thefollowing methods were used. BSA-conjugated glyco-analogs were coatedonto 96-well plates at a concentration of 10 μg/ml and 50 μl/well inHBSS for 2 hours at room temperature. The plates were washed once withHBSS then blocked with HBSS containing 1% BSA for 30 minutes at roomtemperature. The blocking solution was removed and then 2 μg/ml, 50μl/well of mu-anti-LUCA2 in HBSS with 1% BSA was added to each well for1 hour at room temperature. The plates were washed three times withHBSS. Secondary antibody (donkey anti-mouse IgG, H+L-HRP conjugate at aconcentration of 0.1 μg/ml, 50 μl/well) was added to each well for 30minutes at room temperature. The plates were washed three times withHBSS. Color development was induced with 100 μl/well of TMB Substrate(KPL Labs) followed by the addition 100 μl/well of 1M phosphoric acid tostop the reaction. The plates were read at O.D. 450 nm. The graphedresults are shown on FIG. 3. Mu-anti-LUCA bound recognized LNFP-II(Lewis A antigen) and LNFP-III (Lewis X antigen), but not LNFP-I (LewisB antigen) nor LNDFP-I (Lacto-N-difucohexaose I). These results indicatethat mu-anti-LUCA2 recognizes a carbohydrate epitope that is representedby both LNFP-II and LNFP-III.

Example 9 Mu-Anti-LUCA2 Induces Mac-1(CD11b/CD18) Activation

The ability of mu-anti-LUCA2 to affect Mac-1 (CD11b/CD18) dependent T84cell adhesion was tested. T84 cells are an intestinal epithelial cellline that has been used in neutrophil migration assays. It is known inthe art the neutrophils are able to migrate across cultured T84epithelial cell monolayer in a Mac-1 (CD11b/CD18) dependent adhesiveevent. Blocking this Mac-1 dependent neutrophil migration may beimportant in decreasing neutrophil perpetuated chronic inflammation.Purified Mac-1 from normal human neutrophils was diluted in HBSS andcoated onto 96-well plates at a saturating concentration for two hoursat room temperature. The plate was washed and blocked with HBSScontaining 1% BSA for 30 minutes at room temperature before the additionof BCECF labeled T84 cells in antibody containing HBSS/1% BSA. Theantibodies used were mu-anti-LUCA2, TS 1/18, and W6/32. W6/32 is apositive control antibody, known to be able to increase T84 celladhesion. TS 1/18 is a negative control antibody that is known toinhibit Mac-1 dependent T84 cell adhesion. The plate was incubated for 1hour at 37° C. After incubation, the plate is read on a Geminifluorescent plate reader (Molecular Devices) to obtain a pre-washfluorescent signal. The plate is then washed gently by using a 29 gaugeneedle aspiration and HBSS with 1% BSA application three time. Aftereach wash, the plate is read on the Gemini plate reader for post-washfluorescence signal. The percent adhesion is calculated for each wash bythe following equation: 100× (post-wash/pre-wash fluorescence). Theresults of the T84 cell adhesion assay are shown in FIG. 4. There isincreased Mac-1 dependent T84 cell adhesion when mu-LUCA2 is used ascompared to the positive control antibody, W6/32. These results indicatethat mu-anti-LUCA2 is able to bind to Mac-1 and increase T84 celladhesion. The mu-anti-LUCA2 increased T84 cell adhesion is Mac-1specific because T84 cells do not express LUCA2 (as demonstrated throughFACs analysis), therefore ruling out antibody induced cross-linking.These results suggest that mu-anti-LUCA2 is able to increase neutrophiladhesion to epithelial cells and thereby affect neutrophiltransmigration in chronic inflammation.

Example 10 Effect of Mu-Anti-LUCA2 on Pancreatic Tumor Cell Line Hs700T

The ability of the antibodies to reduce cell number in vitro when grownas a monolayer can be assessed using cell monolayers grown in thepresence or absence of varying amounts of test or control purifiedantibody and the change in cell number assessed using MTT. MTT is a dyethat measures the activity of mitochondrial enzymes and correlates withrelative viable cell number. Cells of interest were plated and grown inF12/DMEM (1:1) growth medium supplemented with 10% fetal bovine serum in96 well plates. Hs700T cells were plated at 2000 cells/well intriplicate wells of a 96 well dish. Immediately after plating,mu-anti-LUCA2 was added. The cells were incubated at 37° C. in ahumidified incubator at 5% CO₂ for 5 days. At the end of the assay, MTTwas dissolved in PBS (5 mg/ml) and added directly to wells at 1:10dilution. Plates were placed back in incubator for 4 hours. After theincubation, medium was removed and 100 μl DMSO was added to solubilizethe MTT precipitate. Plates were read at O.D. 540 nm.

At 20 μg/ml mu-anti-LUCA2 inhibited the growth of pancreaticadenocarcinoma cell line Hs700T approximately 40%. Representativegraphed results of the effects of mu-anti-LUCA2 are shown in FIG. 5.

Example 11 Internalization of Mu-Anti-LUCA2 and Toxin-ConjugatedAnti-Mouse IgG

Mab-ZAP (Advanced Targeting Systems, San Diego, Calif.) is an anti-mouseIgG conjugated to saporin, a toxin that inhibits protein synthesis. Thistoxin is impermeable to the cell membrane. If a monoclonal antibody isbound to a cell-surface antigen that is internalizable, thetoxin-conjugate can bind to the bound monoclonal and, thereby, beinternalized and eventually kill the cell. Being dependent uponinternalization for demonstration of toxic activity, the Mab-ZAP canserve to evaluate whether or not a given surface antigen will serve as asuitable target for any toxin that is dependent upon internalization toexpress cell toxic effects. As such, the Mab-ZAP serves as a model forsuch internalization-dependent toxins such as maytansinoids andchalicheamicins.

For testing the internalization of mu-anti-LUCA2 and saporin conjugatedanti-mouse IgG by tumor cells and effect of killing the tumor cellsafter internalization of saporin, human pancreatic adenocarcinoma cells,Hs700T, were removed from stock flasks with 10 mM EDTA and centrifuged.Cells were resuspended at 50,000/ml in appropriate medium and 100 μlplated per well in 96 well plates. Antibody mu-anti-LUCA2 was addedimmediately to appropriate wells as a 10× concentrate, to make a finalconcentration of 10 ug/ml. After 15 minutes at room temperature Mab-ZAP(Cat. # IT-04, Advanced Targeting Systems, San Diego Calif.) was addedto appropriate wells as 10× concentrate, to make final concentrationsfrom 0.001 nM to 10 nM. After 4 days growth, MTT was added (stock 5mg/ml PBS, 1:10 dilution in well) for 4 hrs at 37° C. The medium wasthen removed from all wells and 100 μl/well DMSO was added. The plateswere gently swirled to solubilize the blue MTT precipitate and theplates were read at O.D. 540 nm.

There was a decrease in MTT staining in Hs700T cells in the presence ofmu-anti-LUCA2 as compared to staining in the absence of mu-anti-LUCA2.This indicates that the growth of Hs700T cells was inhibited in thepresence of mu-anti-LUCA2 and Mab-ZAP and these results are indicativeof mu-anti-LUCA2 and toxin-conjugated anti-mouse IgG were internalizedin Hs700T cells.

Results of an internalization experiment according to the methods ofthis Example are shown in FIG. 6.

Example 12 Anti-Tumor Efficacy of Mu-Anti-LUCA2 Antibody in aSubcutaneous Model of Human Pancreatic Adenocarcinoma Using Hs700T Cells

This study was designed to test the dose-responsive anti-tumor data foran anti-LUCA2 antibody in a subcutaneous model of pancreatic cancer.Fluorouracil (5FU), a cytotoxic chemotherapy agent, was used as apositive control and tested to see if there was a cumulative effect withmu-anti-LUCA2 and 5FU.

Cultured Hs700T human pancreatic adenocarcinoma cells were trypsinized,washed in media, spun down and resuspended in media at 100 million cellsper milliliter of media (5 million cells per 0.05 mL volume), then mixedin an equal volume of Matrigel® for a final injection volume of 0.1 mL.72 NCR.nu/nu homozygous mice were dosed intraperitoneally during thestudy. The groups were (1) saline control at 0.2 mL, twice weekly for 10treatments (2) mu-anti-LUCA2 antibody at 50 mg/kg, twice weekly for 10treatments, (3) Fluorouracil (5FU) at 35 mg/kg, once weekly for 4treatments, and (4) mu-anti-LUCA2 antibody at 50 mg/kg and 5FU at 35mg/kg, twice weekly for 10 treatments.

Tumor growth over time was evaluated to determine anti-tumor activity.Tumors were palpable prior to initiation of therapy. Animals respondingto antibody treatment were maintained after treatment cessation todetermine time to tumor regrowth.

Animals treated with 35 mg/kg 5FU showed a significant decrease in tumorvolume (approximately 21.5% inhibition when compared to saline control).Mice treated with 50 mg/kg mu-anti-LUCA2 antibodies and 35 mg/kg 5FUshowed a even more significant decrease in tumor volume than 5FU alone(approximately 32.3% inhibition when compared to saline control).Finally, mice treated with mu-anti-LUCA2 antibodies did not show anyeffect different from saline control. Based on these results there maybe a cumulative effect with 5FU and mu-anti-LUCA2 antibody treatmentover either one alone.

It is understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this application. Allpublications, patents and patent applications cited herein are herebyincorporated by reference in their entirety for all purposes to the sameextent as if each individual publication, patent or patent applicationwere specifically and individually indicated to be so incorporated byreference.

1. A method of treating cancer in an individual comprising administeringto said individual an amount of a composition sufficient to inhibit thegrowth of a cancer cell of said cancer in said individual, wherein saidcomposition comprises a substantially purified immunoglobulinpolypeptide or an antigen-binding fragment thereof associated with achemotherapeutic agent, and wherein: (A) said substantially purifiedimmunoglobulin polypeptide or antigen-binding fragment thereofspecifically binds to an epitope that is specifically bound by theanti-LUCA2 antibody produced by the hybridoma having ATCC Deposit No.PTA-5068, wherein said epitope is expressed on normal neutrophils and onLNCaP prostate carcinoma cells; and (B) said cancer cell is selectedfrom the group consisting of a cancer cell from: an adrenal gland tumor,an AIDS-associated cancer, an alveolar soft part sarcoma, an astrocytictumor, a bladder cancer, a bone cancer, a brain or spinal cord cancer, ametastatic brain tumor, a breast cancer, a carotid body tumor, acervical cancer, a chondrosarcoma, a dhordoma, a chromophobe renal cellcarcinoma, a clear cell carcinoma, a colon cancer, a colorectal cancer,a cutaneous benign fibrous histiocytoma, a desmoplastic small round celltumor, an ependymoma, a Ewing's tumor, an extraskeletal myxoidchondrosarcoma, a fibrogenesis imperfecta ossium, a fibrous dysplasia ofthe bone, a gallbladder or bile duct cancer, a gestational trophoblasticdisease, a germ cell tumor, a head and neck cancer, an islet cell tumor,a Kaposi's Sarcoma, a kidney cancer, a leukemia, a lipoma/benignlipomatous tumor, a liposarcoma/malignant lipomatous tumor, a livercancer, a lymphoma, a lung cancer, a medulloblastoma, a melanoma, ameningioma, a multiple endocrine neoplasia, a multiple myeloma, amyelodysplastic syndrome cell, a neuroblastoma, a neuroendocrine tumor,an ovarian cancer, a pancreatic cancer, a papillary thyroid carcinoma, aparathyroid tumor, a pediatric cancer cell, a peripheral nerve sheathtumor, a phaeochromocytoma, a pituitary tumor, a prostate cancer, aposterious unveal melanoma, a rare hematologic disorder, a renalmetastatic cancer, a rhabdoid tumor, a rhabdomysarcoma, a sarcoma, askin cancer, a soft-tissue sarcoma, a squamous cell cancer, a stomachcancer, a synovial sarcoma, a testicular cancer, a thymic carcinoma, athymoma, a thyroid metastatic cancer, and a uterine cancer.
 2. Themethod of claim 1, wherein said composition delivers saidchemotherapeutic agent to said cancer cell.
 3. The method of claim 2,wherein said chemotherapeutic agent is delivered into said cancer cell.4. The method of claim 1, wherein said substantially purifiedimmunoglobulin polypeptide is the anti-LUCA2 antibody produced by thehybridoma ATCC No. PTA-5068 or progeny thereof.
 5. The method of claim1, wherein said substantially purified immunoglobulin polypeptide is ananti-LUCA2 antibody.
 6. The method of claim 5, wherein the anti-LUCA2antibody is a monoclonal antibody expressed by hybridoma ATCC No. PTA#5068 or by a progeny thereof that produces the anti-LUCA2 antibodyproduced by hybridoma ATCC Deposit No. PTA-5068.
 7. The method of claim1, wherein said substantially purified immunoglobulin polypeptide is anantigen-binding fragment of an anti-LUCA2 antibody.
 8. The method ofclaim 7, wherein the anti-LUCA2 antibody is a monoclonal antibodyexpressed by hybridoma ATCC No. PTA# 5068 or by a progeny thereof thatproduces the anti-LUCA2 antibody produced by hybridoma ATCC Deposit No.PTA-5068.
 9. The method of claim 1, wherein said cancer cell is a cancercell of a breast cancer.
 10. The method of claim 1, wherein said cancercell is a cancer cell of a lung cancer.
 11. The method of claim 1,wherein said cancer cell is a cancer cell of an ovarian cancer.
 12. Themethod of claim 1, wherein said cancer cell is a cancer cell of apancreatic cancer.
 13. The method of claim 1, wherein said cancer cellis a cancer cell of a colon cancer.
 14. The method of claim 1, whereinsaid cancer cell is a cancer cell of a kidney cancer.
 15. The method ofclaim 1, wherein said cancer cell is a cancer cell of a prostate cancer.16. The method of claim 1, wherein said cancer cell is a cancer cell ofa stomach cancer.
 17. The method of claim 1, wherein saidchemotherapeutic agent is a radioactive molecule.
 18. The method ofclaim 1, wherein said chemotherapeutic agent is a cytotoxic agent.